AWS_IOT: Error(-28)

[izaton]

I'm trying to connect to MQTT using ESP32 but I get this error over and over.

Attempting to connect to SSID: //MySSID//
Connected to wifi
E (67286) AWS_IOT: Error(-28) connecting to <xxxxxxxxxxxxx>-ats.iot.eu-central-1.amazonaws.com:8883, 
Trying to reconnect

[gmussi]

I was having the same problem and it turned out it was an authorization error.
I enabled logs for CloudWatch in IOT CORE, and could find the authroization errors there.