For some reason, the vanilla discs won't play in the Phonos jukebox, but will play just fine in the vanilla one. Discs from the Backrooms mod work just fine, though...

If I don't recieve further clarification on this issue, I will close it. Thanks for the report!

Closed due to lack of information.

Really? Could you possibly show a video of the bug? In my experience, the vanilla discs work even with other mods installed

This may also be a compat issue, another one of your mods must be messing with vanilla discs. Please provide more context, possibly with your mod list.