Not receiving COMMAND_ACK after COMMAND_INT message

Hi folks. I got stuck on this kind of problem. I run a pymavlink based script and send MAVLink_mission_item_int_message containing the command MAV_CMD_NAV_WAYPOINT. The provided documentation says that the COMMAND_ACK message should be transmitted directly after sending it to the vehicle but it gets stuck on the line: msg = vehicle.recv_match(type=‘COMMAND_ACK’, blocking=True)
as no acknowledgment message gets back.
I also tried to request this COMMAND_ACK message but it makes no sense as it contains the parameters of the request message but not MAV_CMD_NAV_WAYPOINT. I do really need this acknowledgment message as sometimes when working with OrangeCube it does not accept this command and I have to check why is that.
Ofcourse the vehicle is armed and airborne when executing the script and indeed in 99% executing the script properly (flying to the location).

I provide a minimal working example in the attachment.
test.txt (862 Bytes)

Which firmware version are you using?

amilcarlucas Thanks for response. Here you have all versions:
pymavlink == 2.4.37
arduCopter == 4.3.3 (drone - hardware)
mavproxy == 1.8.59 (SITL)

Update to the latest versions and retest

I did update all packages but this strange behaviour still occurs. I attached screenshot showing that mavproxy gets COMMAND_ACK but pymavlink in the same time does not and it gets stuck waiting.

I compared your screenshot with mine.
My mavproxy showed “COMMAND_ACK” instead of “MISSION_ACK” which could work for vehicle.recv_match(type=‘COMMAND_ACK’, blocking=True)