on Iris & Sodium for 1.18.1, only the main menu plays music from the mod, during gameplay (only tested singleplayer so far) only the default minecraft music is playing. Yes, I have Mod Menu installed and the mod is installed properly, and yes, I tried putting master volume to 0% and back up a lot of times, didn't help either unofortunately.
Affects both Mod Version 1.4.1 and 1.4.0

that makes no sense.

I know it makes no sense. calling it nonsense won't make the issue go away though. kinda wish I could have gotten a less ignorant respond than "that makes no sense".