Channel 0 (0.5m) started hitting 7 Volts on 2023-08-25 at 9:42 UTC, or 2:42 last Friday morning local time.  It was intermittent at first, but as of this morning it is continuous.  Presumably a short has developed somewhere, likely in the probe.  If there is a spare probe, then I think that's the first thing to try swapping out.

The first sign of a short in channel 0 seems to happen here:

(base) [daq@ustar ~]$ data_dump -i 200,510-513 -x hotfilm.xml /data/isfs/projects/M2HATS/raw_data/hotfilm_20230825_* |& egrep ' 7\.' 
2023 08 25 09:42:43.1870       1 200, 510      12     2.1569     2.0216     7.2967
2023 08 25 09:46:02.1870       0 200, 512      12     1.8874     1.8348     7.2177
2023 08 25 10:10:30.1875       1 200, 510      12      2.007     1.8459     7.2689
2023 08 25 10:14:52.1875       0 200, 512      12     1.9778     1.7318     7.2174
2023 08 25 11:03:13.1880       1 200, 510      12      1.962     1.8282     7.2673
2023 08 25 22:21:08.2910       1 200, 510      12     2.3411    0.68967     7.2026
2023 08 25 22:21:31.2910       1 200, 510      12     2.3765    0.73897     7.2588
2023 08 25 22:21:48.2910       1 200, 510      12     2.4567    0.85462     7.1738
2023 08 25 22:21:55.2915       1 200, 510      12     2.3388    0.76678     7.2604
2023 08 25 22:22:04.2915       1 200, 510      12     2.5594    0.80248      7.091
2023 08 25 22:22:05.2915       1 200, 510      12     2.5424     0.7614     7.1185
2023 08 25 22:23:36.2915       1 200, 510      12     2.5616    0.74718     7.0755
2023 08 25 22:23:37.2915       1 200, 510      12     2.6161    0.74118     7.1119
2023 08 25 22:23:39.2915       1 200, 510      12     2.4647    0.78953      7.085
2023 08 25 22:23:44.2915       1 200, 510      12     2.4616    0.80912      7.225
2023 08 25 22:23:55.2915       1 200, 510      12     2.3531     1.0297     7.2455
2023 08 25 22:23:59.2915       1 200, 510      12     2.2909    0.75256     7.2955
2023 08 25 22:24:57.2920       1 200, 510      12     2.3089    0.76836     7.2838
2023 08 25 22:25:09.2920       1 200, 510      12     2.4819       1.54     7.1864

I didn't see any other problems with ch2 except for those two in the dump excerpt above, whereas ch0 keeps showing up intermittently at 7V over the following days.  I don't know why the min goes close to zero, as if the bridge is disconnected, but the max is 7, normally indicating a short.