It was not managed, honestly I should’ve disabled bitlocker, I just never expected it to be a problem.
As to settings for when it installs updates, they didn’t seem to stick or were not always respected in my experience. I spent a bit of effort trying to make sure it wasn’t configured to do that but it would still just go for it anyway if the system ever became idle after midnight or so.
Anyway this story has a happy ending because after that I decided to give daily driving linux another shot, and none of the issues I had experienced previously still exist here.
In fact, incredibly enough I have found on average that the games I play perform better on Linux now than they did on Windows.
And my OS never installs updates without my permission, let alone forcing an unscheduled reboot.
I use a DNS server on my local network, and then I also use Tailscale.
I have my private DNS server configured in tailscale so whether on or off my local network everything uses my DNS server.
This way I don’t have to change any DNS settings no matter where I am and all my domains work properly.
And my phone always has DNS adblocking even on cell data or public Wi-Fi
The other advantage is you can configure the reverse proxy of some services to only accept connections originating from your tailscale network to effectively make them only privately accessible or behave differently when accessed from specific devices