I did not have this issue before v1.12.13.0. I have always run the sound from MSFS on another output source other than the default. On the odd occasion I streamed, it meant only the audio from MSFS went to OBS and not system sounds etc.
I can reproduce the issue using the steps I posted above, 100% of the time (with and without addons in the Community folder).
This is how I got the sounds to stay working:
- Run MSFS
- Go to Options > General > Sound
- Press F12 or click on ‘Reset to Defaults’ (Mine reset to the below)
- Press F11 or click on ‘Apply To Save’
- Press the Windows key on keyboard and type in Sound Settings, click on the result
- Scroll down and click on ‘Advanced sound options’
- Check that ‘Microsoft Flight Simulator’ is set to ‘Default’
(I clicked in the top drop-down box next to ‘Microsoft Flight Simulator’ and changed it to something else then back to ‘Default’) - Close ‘Sound Settings’
- Quit MSFS (I tried with and without rebooting, made no difference)
- Run MSFS
The only changes I made after running MSFS again was some of the levels. i.e. Aircraft Engines and Warnings sounds down to 50%.