Excuse me for late reply. I was on vacation.
I recorded the flow when request is made. Downstream seems fine to me.
ADDED:
I tried to test against latency issues by installing all stack in one position:
GW+GWBRIDGE and SERVER+APP-SERVER+MQTT on other end the problem remains.
Pycom device don’t get pass the OTAA join. I’m loosing my mind on this. Over TTN as stated works as expected.