In Ubuntu we always prefer whichever device connected most recently, which is probably your wireless headset. To disable this feature try editing /etc/pulse/default.pa and commenting out some or all of these:
### Should be after module-*-restore but before module-*-detect load-module module-switch-on-port-available ### Use hot-plugged devices like Bluetooth or USB automatically (LP: #1702794) .ifexists module-switch-on-connect.so load-module module-switch-on-connect .endif ** Changed in: pulseaudio (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1888041 Title: default output is ignored and reset after reboot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1888041/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs