I would really appreciate some help here, cause I am stuck for almost a week now. I have a brand new F405 wing and an L9R receiver. For some reason I get no sbus signal from the L9R to the FC. The receiver is linked and working ok from regular channels, and the FC seems to work ok.
I have followed all the instructions, setting serial RX for UART2, sbus as communication protocol , checked for continuity from the top of the pin to the back of the board, but no resolve.
Unfortunately i don't have another FC or sbus receiver to cross check....
Any help will be REALLY appreciated at this point. Thanks

Try: serialrx_inverted = off in CLI?
It's very hard to know if your RX and FC is working as expected without having spare part to test.
Do you use SBUS RX in a quad you can remove to test? and test your L9R on a FC in a quad?