I switched to the Alpha release channel and it immediately installed an OS update: 2025102801
I too can confirm that the UBS key app is working again normally.
I set the release channel back to Stable. I expected it to downgrade the OS somehow but nothing happened. I guess it's because Android cannot be downgraded but only upgraded. My understanding is now that with the current release channel setting set to Stable, the next stable update will be installed on the phone.