diff --git a/drivers/SmartThings/matter-lock/src/init.lua b/drivers/SmartThings/matter-lock/src/init.lua
index 4f58e960e9..09f384ee4e 100755
--- a/drivers/SmartThings/matter-lock/src/init.lua
+++ b/drivers/SmartThings/matter-lock/src/init.lua
@@ -83,7 +83,13 @@ local function lock_state_handler(driver, device, ib, response)
   }
 
   if ib.data.value ~= nil then
-    device:emit_event(LOCK_STATE[ib.data.value])
+    local event = LOCK_STATE[ib.data.value]
+    if event ~= nil then
+      device:emit_event(event)
+    else
+      device.log.warn(string.format("Received unknown lock state value (%s), emitting unknown", ib.data.value))
+      device:emit_event(attr.unknown())
+    end
   else
     device:emit_event(LOCK_STATE[LockState.NOT_FULLY_LOCKED])
   end
diff --git a/drivers/SmartThings/matter-lock/src/test/test_matter_lock.lua b/drivers/SmartThings/matter-lock/src/test/test_matter_lock.lua
index 2477e2745b..9693289951 100644
--- a/drivers/SmartThings/matter-lock/src/test/test_matter_lock.lua
+++ b/drivers/SmartThings/matter-lock/src/test/test_matter_lock.lua
@@ -191,6 +191,29 @@ test.register_message_test(
   }
 )
 
+test.register_message_test(
+  "Handle unknown LockState value from Matter device.", {
+    {
+      channel = "matter",
+      direction = "receive",
+      message = {
+        mock_device.id,
+        clusters.DoorLock.attributes.LockState:build_test_report_data(
+          mock_device, 10, 0xFF
+        ),
+      },
+    },
+    {
+      channel = "capability",
+      direction = "send",
+      message = mock_device:generate_test_message("main", capabilities.lock.lock.unknown()),
+    },
+  },
+  {
+     min_api_version = 17
+  }
+)
+
 test.register_message_test(
   "Handle received BatPercentRemaining from device.", {
     {
diff --git a/drivers/SmartThings/samsung-audio/src/command.lua b/drivers/SmartThings/samsung-audio/src/command.lua
index deca7c4416..d03fe07850 100644
--- a/drivers/SmartThings/samsung-audio/src/command.lua
+++ b/drivers/SmartThings/samsung-audio/src/command.lua
@@ -34,6 +34,19 @@ local function is_empty(t)
   return not t or (type(t) == "table" and #t == 0)
 end
 
+local function get_uic_response(ret, command_name)
+  local root = ret and ret.handler_res and ret.handler_res.root
+  local uic = root and root.UIC
+  local response = uic and uic.response
+
+  if not uic then
+    log.warn(string.format("Missing UIC data in %s response", tostring(command_name)))
+    return nil, nil
+  end
+
+  return uic, response
+end
+
 local function tr(s,mappings)
   return string.gsub(s,
       "(.)",
@@ -94,8 +107,9 @@ function Command.volume(ip)
   if ip then
    local url = format_url(ip, "/UIC?cmd=<name>GetVolume</name>")
    local ret = handle_http_request(ip, url)
-   if ret then
-     response_map = { volume = ret.handler_res.root.UIC.response.volume, }
+   local _, response = get_uic_response(ret, "GetVolume")
+   if response and response.volume ~= nil then
+     response_map = { volume = response.volume, }
    end
   end
   return response_map
@@ -114,8 +128,9 @@ function Command.set_volume(ip, level)
    local encoded_str_vol = "/UIC?cmd=%3Cpwron%3Eon%3C/pwron%3E%3Cname%3ESetVolume%3C/name%3E%3Cp%20type=%22dec%22%20name=%22volume%22%20val=%22" .. level .. "%22%3E%3C/p%3E"
    local url = format_url(ip, encoded_str_vol)
    local ret = handle_http_request(ip, url)
-   if ret then
-     response_map = { volume = ret.handler_res.root.UIC.response.volume, }
+   local _, response = get_uic_response(ret, "SetVolume")
+   if response and response.volume ~= nil then
+     response_map = { volume = response.volume, }
    end
   end
   return response_map
@@ -326,8 +341,9 @@ function Command.getMute(ip)
   if ip then
    local url = format_url(ip, "/UIC?cmd=<name>GetMute</name>")
    local ret = handle_http_request(ip, url)
-   if ret then
-     response_map = { muted = ret.handler_res.root.UIC.response.mute,}
+   local _, response = get_uic_response(ret, "GetMute")
+   if response and response.mute ~= nil then
+     response_map = { muted = response.mute,}
    end
   end
   return response_map
@@ -342,8 +358,9 @@ function Command.getPlayStatus(ip)
   if ip then
    local url = format_url(ip, "/UIC?cmd=<name>GetPlayStatus</name>")
    local ret = handle_http_request(ip, url)
-   if ret then
-     response_map = { playstatus = ret.handler_res.root.UIC.response.playstatus,}
+   local _, response = get_uic_response(ret, "GetPlayStatus")
+   if response and response.playstatus ~= nil then
+     response_map = { playstatus = response.playstatus,}
    end
   end
   return response_map
diff --git a/drivers/SmartThings/samsung-audio/src/handlers.lua b/drivers/SmartThings/samsung-audio/src/handlers.lua
index 6233a86326..65a0027bf9 100644
--- a/drivers/SmartThings/samsung-audio/src/handlers.lua
+++ b/drivers/SmartThings/samsung-audio/src/handlers.lua
@@ -137,7 +137,7 @@ end
 function CapabilityHandlers.handle_audio_notification(driver, device, cmd)
   local ip = device:get_field("ip")
   local mute_status = command.getMute(ip)
-  if mute_status.muted ~= "off" then
+  if mute_status and mute_status.muted ~= nil and mute_status.muted ~= "off" then
      --unmute before playig notification
      command.unmute(ip)
   end
diff --git a/drivers/SmartThings/samsung-audio/src/init.lua b/drivers/SmartThings/samsung-audio/src/init.lua
index de1958ff25..2e51b8e0b4 100644
--- a/drivers/SmartThings/samsung-audio/src/init.lua
+++ b/drivers/SmartThings/samsung-audio/src/init.lua
@@ -94,14 +94,23 @@ local function emit_refresh_data_to_server(driver, device, cmd)
 
   -- get volume
   local vol = command.volume(device:get_field("ip"))
-  device:emit_event(capabilities.audioVolume.volume(tonumber(vol.volume)))
+  local current_volume = vol and tonumber(vol.volume)
+  if current_volume ~= nil then
+    device:emit_event(capabilities.audioVolume.volume(current_volume))
+  else
+    log.warn("Unable to read speaker volume from refresh response")
+  end
 
   -- get mute status
   local muteStatus = command.getMute(device:get_field("ip"))
-  if muteStatus.muted ~= "off" then
-    device:emit_event(capabilities.audioMute.mute.muted())
+  if muteStatus and muteStatus.muted ~= nil then
+    if muteStatus.muted ~= "off" then
+      device:emit_event(capabilities.audioMute.mute.muted())
+    else
+      device:emit_event(capabilities.audioMute.mute.unmuted())
+    end
   else
-    device:emit_event(capabilities.audioMute.mute.unmuted())
+    log.warn("Unable to read speaker mute state from refresh response")
   end
 end
 
diff --git a/drivers/SmartThings/zigbee-switch/src/zll-polling/init.lua b/drivers/SmartThings/zigbee-switch/src/zll-polling/init.lua
index b464b30acc..814e0f70ce 100644
--- a/drivers/SmartThings/zigbee-switch/src/zll-polling/init.lua
+++ b/drivers/SmartThings/zigbee-switch/src/zll-polling/init.lua
@@ -5,36 +5,63 @@ local device_lib = require "st.device"
 local clusters = require "st.zigbee.zcl.clusters"
 local configurationMap = require "configurations"
 
-local function set_up_zll_polling(driver, device)
-  local INFREQUENT_POLL_COUNTER = "_infrequent_poll_counter"
-  local function poll()
-    local infrequent_counter = device:get_field(INFREQUENT_POLL_COUNTER) or 1
-    if infrequent_counter == 12 then
-      -- do a full refresh once an hour
-      device:refresh()
-      infrequent_counter = 0
-    else
-      -- Read On/Off every poll
-      for _, ep in pairs(device.zigbee_endpoints) do
-        if device:supports_server_cluster(clusters.OnOff.ID, ep.id) then
-          device:send(clusters.OnOff.attributes.OnOff:read(device):to_endpoint(ep.id))
-        end
+local INFREQUENT_POLL_COUNTER = "_infrequent_poll_counter"
+local ZLL_POLL_TIMER = "_zll_poll_timer"
+
+local function do_zll_poll(device)
+  if device == nil or type(device.get_field) ~= "function" then
+    return
+  end
+
+  local infrequent_counter = device:get_field(INFREQUENT_POLL_COUNTER) or 1
+  if infrequent_counter == 12 then
+    -- do a full refresh once an hour
+    device:refresh()
+    infrequent_counter = 0
+  else
+    -- Read On/Off every poll
+    for _, ep in pairs(device.zigbee_endpoints) do
+      if device:supports_server_cluster(clusters.OnOff.ID, ep.id) then
+        device:send(clusters.OnOff.attributes.OnOff:read(device):to_endpoint(ep.id))
       end
-      infrequent_counter = infrequent_counter + 1
     end
-    device:set_field(INFREQUENT_POLL_COUNTER, infrequent_counter)
+    infrequent_counter = infrequent_counter + 1
   end
+  device:set_field(INFREQUENT_POLL_COUNTER, infrequent_counter)
+end
 
+local function set_up_zll_polling(driver, device)
   -- only set this up for non-child devices
-  if device.network_type == device_lib.NETWORK_TYPE_ZIGBEE then
-    device.thread:call_on_schedule(5 * 60, poll, "zll_polling")
+  if device.network_type ~= device_lib.NETWORK_TYPE_ZIGBEE then
+    return
+  end
+
+  -- should never happen, but defensive check
+  local existing_timer = device:get_field(ZLL_POLL_TIMER)
+  if existing_timer ~= nil then
+    device.thread:cancel_timer(existing_timer)
+  end
+
+  local timer = device.thread:call_on_schedule(5 * 60, function()
+      do_zll_poll(device)
+  end, "zll_polling")
+
+  device:set_field(ZLL_POLL_TIMER, timer)
+end
+
+local function remove_zll_polling(driver, device)
+  local existing_timer = device:get_field(ZLL_POLL_TIMER)
+  if existing_timer ~= nil then
+    device.thread:cancel_timer(existing_timer)
+    device:set_field(ZLL_POLL_TIMER, nil)
   end
 end
 
 local ZLL_polling = {
   NAME = "ZLL Polling",
   lifecycle_handlers = {
-    init = configurationMap.reconfig_wrapper(set_up_zll_polling)
+    init = configurationMap.reconfig_wrapper(set_up_zll_polling),
+    removed = remove_zll_polling
   },
   can_handle = require("zll-polling.can_handle"),
 }
diff --git a/drivers/SmartThings/zigbee-valve/src/sinope/init.lua b/drivers/SmartThings/zigbee-valve/src/sinope/init.lua
index ab3786511c..0c6994ad00 100644
--- a/drivers/SmartThings/zigbee-valve/src/sinope/init.lua
+++ b/drivers/SmartThings/zigbee-valve/src/sinope/init.lua
@@ -12,7 +12,9 @@ local PowerConfiguration = clusters.PowerConfiguration
 local function device_init(driver, device)
   battery_defaults.use_battery_voltage_handling(device)
   -- according to the DTH, this attribute cannot be configured for reporting
-  device.thread:call_on_schedule(900, function() device:send(PowerConfiguration.attributes.BatteryVoltage:read()) end)
+  device.thread:call_on_schedule(900, function()
+    device:send(PowerConfiguration.attributes.BatteryVoltage:read(device))
+  end)
 end
 
 local function battery_voltage_handler(driver, device, command)