WetGeek As before, when I rebooted, my Bluetooth was disabled.
Team, any idea what might be doing this? The first time it happened, it took me by surprise. It had never happened in all the years I've been doing weekly updates. All I knew was that my mouse didn't work, and my keyboard didn't work. I could do nothing with this laptop. So I used that occasion to reinstall the OS, making some small improvements as I did.
The next week, I accidentally found out that Bluetooth was disabled after the update, so I dug out a wireless mouse, plugged the dongle in, and used that mouse to enable Bluetooth in the system settings. That's all it took to make my mouse and keyboard both work normally again. They even connected automatically.
So, every week since then I've known what to do, and it doesn't take me long to enable things again, but it's really annoying. Plasma system here. Low priority problem. If I should file a bug report, let me know and I'll do that.