I have no idea about that behavior or what to do with it but for additional sound settings, you could install pavucontrol (sudo apt install pavucontrol and launch from terminal with pavucontrol) just in case it has something that helps.
A random thing to try would be to remove the config and do a re-installation to re-set them, just in case that has something to do with it (although that issue and solution may not have anything to do with this). Like this: Byzantium backports unofficial - #334 by JR-Fi