I just changed my Diatone R349 flight controller because the old one broke. On my first test flight, I noticed the OSD is flickering very bad, sometimes losing it for more than 1 second, even when not armed.
The video feed is good, just the OSD flickering.
The VTX and camera are powered by an external 5v regulator. The rest is powered by the FC.
I've read that it could be a ground issue.
Could it be something else?