Omnibus F4 V3 Flight Controller looses receiver signal

Just finished building my Chameleon with Airbot 4-in-1 ESC and Omnibus F4 V3 flight controller. I previously had Omnibus F4 Pro but I fried it thanks to having the ESCs on flipped over so I read the wiring diagram wrong and connected VBAT to M4 pin… duh.

Ok, but now with the new FC I have a problem that I do get my XSR receiver to bind with Taranis, it works ok and then some time is just stops working. I does not loose connection with Taranis, but there is just no input coming to the flightcontroller. I have tried this with two different receivers, XM+ (that I had on when I fried the previous FC) and a fresh XSR.

Using SBUS, the jumper soldered to SBUS setting. Power coming from the FC to the receiver. I don’t have anything going to RAM bus, no 5V or VBAT. FC is powered via VBAT.

Other than getting yet another board and trying out, is there anything I might try to debug this? Starting to sound like an issue in the FC (hardware or configuration).

What is your CPU ultiisation withn betaflight? And it might be related to this issue with DMA mode on SDcard logging -

But I am not sure if that is the same issue but might be worth disabling blackbox logging temporarily to see if anything changes