I may have found a solution. It's now been working for 3 days in a row.
As a troubleshooting step, I went to gboard app settings and selected "clear storage". Then I once again followed the process Kras outlined, and it seems to have worked. Network permission is revoked, and speech-to-text works as before. I needed to reset some minor settings for gboard (like the theme) but that was it.
I did try clearing the cache first, then redoing the "Kras process" but that didn't work. I had to fully clear storage for gboard.
If someone else (Kras?) could test this to confirm it works for them as well, I believe this issue could be closed after successful confirmation.