You're not the only one, unfortunately. I've had multiple Linux users report that the most recent working version is 0.5.1. My only suspicion is the build of Godot I'm using now. Since 0.5.2, I've been using a custom build that fixes the microphone issue for a lot of users. Best guess I have is that it, as a consequence, breaks something for some Linux users. I'm hoping Godot officially releases a version that doesn't have the mic issue (haven't been holding my breath), but until then I don't have a clean solution--assuming the custom build is actually the issue. Sorry about this.
Viewing post in Version 0.5.3 released - Dub preservation update comments
Unfortunate that's the case and totally understandable. I appreciate the transparency. I actually did end up figuring out how to make it work by actually adding the game as a non-steam game and running through it's own proton. Only issue is that the datapack location is placed very very far away deep in file systems. Regardless, thank you so much for the reply! And still looking forward to more updates for the game