Hi,
I tried to send in ABP mode with an Heltec HTCC-AB02S, and a HT-M01 gateway. On the Chirpstack server I’ve got a ConfirmedMessage received. But the Ack is never received on the device and thus it keeps sending during the 4 trials. The RX1 delay is fixed to the default 1second on the server, and it seems to be the case on the device too.
Where should I investigate further more ? 
Device configuraiton:
AT Rev 1.3
+AutoLPM=1
+LORAWAN=1
+KeepNet=0
+OTAA=0
+Class=A
+ADR=0
+IsTxConfirmed=1
+AppPort=2
+DutyCycle=120000
+ConfirmedNbTrials=4
+ChMask=000000000000000000000001
+DevEui=0200000000000002(For OTAA Mode)
+AppEui=0000000000000000(For OTAA Mode)
+AppKey=02000000000000000000000000000002(For OTAA Mode)
+NwkSKey=02000000000000000000000000000002(For ABP Mode)
+AppSKey=02000000000000000000000000000002(For ABP Mode)
+DevAddr=02000002(For ABP Mode)
Here is the chirpstack received message :
