A few thoughts.
- That device waveform might not be correct, so don’t puzzle too long on it. It’s not an exactly measured thing. You can delete that device and Sense could end up redetecting with a different look.
- My old school AC garage door has been natively detected plus I have one on a smartplug. You can see what both device waveforms look like here.
LiftMaster 8355W AC Motor Garage Door Opener - #3 by kevin1