the CPDLC in inibuilds a340 not responding on aircraft's panel, I tryed a solution that works for me and is as follow:
1) ADIRS has to be aligned
2)verify in EFB that CPDLC is set to BYATC
3) compile and send departure clearance request and wait till BYATC app respond with clearance via text ON THE APP ,not the aircraft panel where it doesn't works at the moment
4) change in EFB CPDLC to HOPPIE
5) compile again the departure clearance request exactly as before and send again
6)in EFB reset CPDLC to BYATC
7) WAIT and you will receive the reply correctly in Aircraft system
IMPORTANT ADIRS must be aligned before trying this procedure
reported also to BYATC team hope that someone could help solving this bug. thank you