To the OP, mine does the same thing. We run the AC all night with the fan on high. Turn it back to auto, won't shut off. Adjust t-stat up to some unrealistic setting, won't turn off. No matter what, we have to turn it to off. Then, you can turn it back on in auto and all is well.
This is AFTER replacing the t-stat and control box in the AC. Still does it. Original, and replacements did the same thing. We just live with it and it's become the norm to just turn it to off in the morning.
This is one of the new / smaller Dometic 15k BTU units with the small digital t-stats.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.