Try using Bluetooth instead (with the approved Bluetooth adapter). I had all sorts of problems with ANT+ and PowerMatch when I first started, most notably that when it dropped, the power would stay wherever it was at until I paused it which was a nightmare during intervals. Felt to me like ANT+ got a lot of interference with other wireless stuff around my setup.
Bluetooth is much more stable. I still get the occasional drop or funny things like it not adjusting resistance accordingly for a few seconds but overall it’s a much better experience. Using the trainer power is the absolute best in terms of consistency throughout the workout but I hate that it reads about 10% lower than my PM (making workouts harder than they should be if I have it set using a FTP guaged from my PM instead) and I like to keep it the same as the readings outdoors.