Thank you for the reply , the handheld I was using on the M8 is the SPM1320 combo that comes with all the sensors and the little receiver and I'm using for receiver the SR3000 and everything was working fine on the M8 but I get no read out no temp , rpm or voltage but the signal is at it full ! I'm thinking I should go back to my M8 since I hace telemetry on 3 of my buggies :-(
Thank you for your help !!!

It's a while back now, but I don't recall doing anything other than what was in the instructions. Link the handheld to the module, and that was about it. Funny timing, I just today ordered the 4PX, taking another kick at the telemetry. Hopefully it's much improved in the years! I never used it with an M8, but it did work with my M11. Not sure why Spektrum would say it won't work unless you're using a newer DSM module from Spektrum that doesn't support the telemetry handheld. Maybe that's it?