You're not the only one to report this, and I only have one suspicion at the moment that I cannot confirm. Version 0.5.1 was using the main branch of Godot 4.4.1, and Versions 0.5.2 and onward use a custom build that fixes the microphone recording issues for hundreds of players.
My only theory at the moment is that that custom build is causing crashes for some Linux users, but I have no way to confirm that at the moment. If it's bad enough, I might have to try backporting newer versions to the main branch of Godot and exporting it there, and see whether it's magically fixed.