RPi3: onboard Bluetooth gone after upgrades

Installation
1

My RPi3 installation has lost its onboard Bluetooth lately. I have changed literally nothing except installed recent upgrades (now core 2023.12.1, supervisor 2023.11.6, OS 11.2). I believe this happened with the OS upgrade.

I tried removing the Bluetooth integration, but it refuses to reinstall (“no adapters found”). Config/hardware doesn’t show anything starting with “hci” (not sure if it even should). Where do I go from here?

2

Update: after verifying with Raspbian that there was nothing wrong with my RPi, I did a full reinstall. Bluetooth works now as if nothing happened. Something must have gone wrong during one of the earlier updates.

On a side note, this was not a nice way to learn that the automatic backups made during core updates are only partial.