Omnibus F4 V6 does not see serial Spektrum receiver

I am having a struggle with the receiver communication with the FC. Running a spectrum FPV racing serial receiver wired to 3V3 and TX1 the protocol set in either I-nav or Betaflight (have flashed both trying to resolve this) the Serial Receiver on UART1 and speksat / Spektrum2048 I get nothing @ the Transmitter Tab at all. I have tried other cables / different receivers to no avail. CPU based serial ports are disabled.
Am I missing something simple, I cannot find any assistance on other the WEB / Forums etc.

Can you link your RX please?

It should work on UART1, but I assume you have enabled serialRX on the ports tab?

Otherwise you could also try connecting it to the UART 2 just to check.

But I agree that we need to know what Rx you are using to help. As some spectrum ones can actually output ppm or even sbus.

Thanks Guys looks like it was a dry joint on UART1 looked great but just heated the joints again as the earth looked a little dodgy (even though the receiver was powering up and binding) all working now… Thanks again.

well done in finding a fix