JoinRequest JoinAccept Loop and device never seen

I already saw a couple of similar issues there but without any solution. I have chirpstack 4.8.1 on the docker infra - this is based on the example which was posted GitHub - chirpstack/chirpstack-docker: Setup ChirpStack using Docker Compose. Our region is EU868 so same as on the default docker configuration so I not had to changed a lot of configuration there. My gateway is mikrotik wAP LR8 which is also for region EU868.

Everything seems to be OK but my endpoints are still on the join loop - sending joinRequests and receiving joinAccepts but no other messages…I can see device Events “join” and loRaWAN frames on the chirpstack GUI, mikrotik traffic also shows Rx and Tx messages as you can see below:

but no another uplink and downlink…Last seen attribute is marked as “Never”.
I tried 2 different end devices - bmeter watermeter and heltec ESP32 lora v3 - both with the same behaviour.

Any suggestion what could be root cause of this behaviour.