Okay, 1:00 AM, but still...
So last night I got set up and got things rolling by about 8:30 PM last night, collecting H-alpha for a couple hours until 10:45, then more still until 1:30 (I pause to manually check focus). I dither every three subs and most of the time I have no issues with dithering. Everything had been going well including meridian flip. I switched to SII at around 1:30, refocused, got everything started up again, and went to bed for the night.
When I came down to cover everything up for the day I saw that I had been getting error messages continually from about 2:00 AM onwards - a "PHDError: Dither error CODE: 1" every 5 minutes through the end of my run. Running a quick blink/subframe selector, found that I needed to pitch all but 9 of ~40 subs collected between 1:30 and 4 (when my target gets too close to the trees).
I'd already run a PHD calibration in the evening before I started, and hadn't taken anything down or changed anything from previous runs which worked without this issue, so I'm not sure if this a NINA glitch or a PHD2 issue, or something else entirely?
Really, the only thing that was different was that the nighttime temperature was colder than the last time things ran differently. Stupid ues, but really nothing else has changed so it's kind of baffling where these nonsense errors come from that pop up and kill your data.