Uupload mission doesn't work

Hi there
I am trying to upload a mission with my tablert nexus 7 on my custom built huge X8 with a legit pixhawk.
I can connect it both with telemetry and USB but every time I try to upload a mission it just sit idle. If there are no waypoints the voice confirm waypoint loaded but if there is even only one waypoint the voice won’t confirm waypoint loaded and there is no mission to download. Can someone help me and tell me if tower is supposed to work with any pixhawk on a custom build, 9r if there is something I m missing?
Thanks f9r the help

I’m having the same issue. Connects fine, but both uploading, and downloading a mission do nothing (no sound, confirmation, nor errors). I can pull out my laptop and both upload and download via QGC, so I know it’s not an issue with the pixhawk. I’m running the latest PX4 firmware. I’m also experiencing the problem mentioned on another post that the flight mode is always unknown.