Well, it looks like reverting to Stable seemed to at least partially fix it for me. The keyboard is still higher on the screen, but at least it fits to the screen width correctly. Thanks!
I couldn’t find any mention of anyone else with this issue around the web or on valve’s GitHub issue tracker, so I assumed it was something dumb I’d done rather than a bug.
MossyFeathers@pawb.social 10 months ago
I’m on the stable branch and have this issue, so not a beta bug.