Same problem here. Dell XPS 13 working sweetly with Bose QC35 II and QC45 with Windows 10, but since upgrade to Windows 11, nothing but problems.
Windows Audio service stops, Spotify (no audo and hangs, need to kill app), Youtube (video just spins), Teams all stop processing audio. Rebooting the PC fixes it, but it reoccurs again if headphones are turned off/charged or laptop goes to sleep.
It's driving me crazy as I use Bluetooth headphones all day, every day.