I have a problem on a Eachine X220s with FC Omnibus F4 V3 and IA6B receiver.
The receiver is configured with the IBUS protocol and i set the UART6 as a serial RX.

After about two minutes of normal use, the signal becomes intermittent.

This is the video of the problem:

If i set the rotation of the engines through betaflight, they rotate without interruption.

I turned off routers and mobile phones thinking of any interference, but the situation remains the same.
I did a test even with the VTX disconnected.
What could be the problem?