Presumably Audacity probes all devices when it launches and doing so enables Optical Raw. Probably any application using PortAudio would do the same. You said in https://forum.audacityteam.org/t/can-hear-midi-but-cant-record-it-reprise-solved/34987/17 that other applications also turned off sound by unmuting Optical Raw.
There is a thread at https://forum.audacityteam.org/t/system-sound-crashes-on-audacity-start/27419/1 about SoundBlaster Audigy 2 losing sound on launching Audacity, but it isn’t clear if Optical Raw was the cause. There is a suggestion there that the issue started in Audacity 1.3.13 Beta, but I don’t recommend trying to use 1.3.12. You could try using Audacity 2.0.5 for Windows under WINE.
Do you ever use Optical Raw? If not perhaps you can disable it in a configuration file or script such as .asoundrc ? I am only a casual Linux user so you will have to wait for Steve to tell you if that is a possibility.
Gale