No such issues here with my XM5, been using mine for over an year. Are your devices on at least Bluetooth v5.2? All of mine are either 5.2 or 5.3 and I’ve not experienced any issues. I use my headphones with Android, Linux, Windows 10 and macOS. Even multipoint works fine.
As for the head comfort, you could get a headband cover/cushion, such as the ones made by Geekria.