I honestly think there are good batches and bad ones of the QC35s. I have gen 1 and they are rock solid with the connections, never fail. Have coworkers who would swear by theirs too, while others have similar complaints as you do.
FWIW, I love my Airpods Pro and it's insane that neither Sennheiser nor Bose could beat Apple to the punch with something that works as well as those do. That being said, my Airpods Pro aren't without issues: they seem to hate my iMac. Not even the Big Sur update could change my Airpods' aversion towards reliably connecting to it.
Concur—I have the QC35, I’ve given up with all the endless niggles of multiple device support and limited them to just the phone which is my use case 95% of the time.
Yeah, my connectivity story with these got so bad at one point I ended up with two pairs, each with a little sticker telling which is for my laptop and which is for my phone. Ironically, connectivity improved with FW updates...
I use the app and "flawlessly" is a joke. The app doesn't even connect to the headphones reliably, even if they're paired and I'm listening to audio through them. Maybe 10% of the time I have to force-close the app and power cycle the headphones for the app to connect.
