Drone not sending MISSION_REQUEST_INT after initial MISSION_COUNT

Hi everyone. I’ve run into an issue where I am able to send a MISSION_COUNT messages (as per the mission protocol) to a drone, but the drone does not respond with the necessary MISSION_REQUEST_INT in order to process each waypoint. This is working fine in the SITL, and other messages such as COMMAND_LONG and PARAM_SET are taken onboard by the drone. Does anyone have any ideas? Thanks in advance!

What PX4 version is that?

Have you considered using MAVSDK for mission upload. It basically takes care of that meta protocol, getting the right messages back and forth.