Child portal problem

[DNNhost]

The module works fine on a single language portal 0
a child portals with 3 languages gives

DesktopModules/IdentitySwitcher/API/identityswitcher/getusers?searchtext=&selectedsearchitem=&onlyDefault=false
400 (Bad Request)

Possibly unhandled rejection: {"data":{"Message":"Specified page is not in this site."},"status":400,"config":{"method":"GET","transformRequest":[null],"transformResponse":[null],"jsonpCallbackParam":"callback","headers":{"PortalId":13,"ModuleId":10509,"TabId":"2067","Accept":"application/json, text/plain, /"},"url":"/DesktopModules/IdentitySwitcher/API/identityswitcher/getusers?searchtext=&selectedsearchitem=&onlyDefault=false"},"statusText":"Bad Request","xhrStatus":"complete"}

is there an easy fix ?