Today I swapped a Spektrum DSMX satellite RX for a Lemon RX 8-channel, with PPM output. I tested and calibrated before sticking down the hardware with foam tape. The new receiver bound and connected on the first try. All of the other hardware seemed happy as well. RC calibration worked perfectly. When testing afterward, I can't get past a RC not calibrated error. I've recalibrated several times. I put the old RX back in. Same result.
The funny thing is, the ESCs chirp as though I hadn't performed ESC calibration. I've repeated that too. They don't stop chirping when I hold the safety switch.
This copter flew this morning. I'm stumped. Any help would be appreciated.