MusicBee & CD ripping: another application is preventing access to the ripped files so they can't be encoded

[Petrosophia]

Hey y'all, absolutely love Bottles so far! I'm running into an issue with MusicBee while trying to rip CDs. I think I've settled the permissions with Flatseal, but I'm getting the following error when I try ripping. Specifically it seems like it'll rip but is unable to encode the file, making the rip useless.

encoding failed: Sharing violation. This file cannot be updated as another application has this file open at the same time.
C:\users\steamuser\Temp\MusicBee_000002.wav

1. What's keeping MusicBee from modifying the file?
2. Why is this happening under the steamuser user instead of my username?
3. Why is steamuser even available in the first place in this Bottle? It was set up under the Application profile, not Gaming.