1. Right click Sounds mixer notification in Windows 10
2. Click sounds then go to the playback device
3. Right click the device you are using and disable
The next highest priority device is used like how windows will chooe a new default device once it the other default device gets disabled.
Spotify continues playing the song, but out of no device. Needs to be restarted to fix, but this is irritating to do every time I want to switch from speakers to my headphones. Changing the default device is not possible in my case and it must be disabled