Voice memo randomly corrupt, Show in Finder doesn't work for any voice memo

Noticed issues with Voice Memos on macOS Tahoe 26.1. Upgrading to 26.2 didn't fix.

(1) The 2nd of two voice memos recorded on the same day seemed to become corrupt. The voice memo wouldn't play in the Voice Memos app, and I couldn't export it (e.g. nothing appeared when dragging/dropping onto desktop). When I manually located the file in ~/Library/Group Containers/group.com.apple.VoiceMemos.shared/Recordings, opening the m4a showed the error "The file isn’t compatible with QuickTime Player". The workaround was to import the m4a into a DAW (e.g. Audacity), where the audio could be heard, and export from there. I didn't do anything unusual that would've made the voice memo corrupt.

(2) Right-clicking on a voice memo (in All Recordings) and selecting Services > Show in Finder: nothing happens.

Reported to Apple. Would appreciate any suggestions in the meantime.