Thanks for replying and the detailed list of options to check for.

I have only the one apple device, the MBP on which the issue is occurring.

Until you made this comment I was unaware of the existence of a shortucts app so I definitely never made any shortcuts. (Incidentally, does this differ much from Automator? Maybe I should look in to this). I wonder if creating a shortcut attached to an automation that triggers a focus state is something easily done accidentally, because I definitely wouldn't have done so on purpose. I did once create an automation to close a specific app at a certain time in the morning (3 hours later than the time I noticed the do not disturb was switched on), but that was supposed to execute once on a specific calendar date and as far as I knew did only it's intended job.

If I look at the do not disturb settings, there are no allowed people and no allowed apps that can display notifications in do not disturb mode, and until I attempted to mess with it just before posting this, there was nothing in the set a schedule section and nothing in the focus filters section. As of now, there is an item in the schedule section, which is that the state should be on while in the location Antarctica, which I hoped would prevent it ever executing as I'm unlikely ever to be there and am not there right now. Before putting this schedule item in place I also attempted to set an actual time based schedule that was supposed to trigger one minute later than the current time as I attempted the fix and scheduled to run for exactly one minute on the logic that hopefully it would trigger do not disturb to only ever operate for 1 minute making it as close as I could effectively get to "off"

I don't know if anything's been 'learned' that could be triggering this, but then again that's kind of the crux of the problem. I'm instinctively resistant to the machine 'learning' anything and then executing without my involvement at any stage. I must admit that's perhaps irrational, after all it 'learned' that I usually operate plugged in and decided to start a charging regimen where it only charges to 80% to extend the life of the battery and I thought that was pretty great but nonetheless, the exact implications of focus states aren't immediately clear to me and they aren't something I sought out or felt a need for so while they perhaps offer some benefit, once they are imposed I'm immediately resistant.

Anyway diatribe aside, it doesn't look like anything I was able to check in with your help could likely be responsible for the behaviour. I think it is likely related to time, as it was around 12:30 AM. It could be related to being off power and in battery mode which isn't something I'd likely do after midnight very often but I couldn't say. I believe I've seen this at least a couple of times whilst plugged in as well. Thanks anyway, let me know if you have any other suggestions to make it stay off now that I've at least switched it off.