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.
QC35 II.