Is it a programmable T-stat?
If it has a time & temp program set into it, it might just be going to what the programmed temp is at the programmed time. If there is a hold button/switch, turning that on should retain whatever temp you have manually set into it.
Might check the batteries also. Being a digital t-stat, it has to have a battery for the display window. A low battery might affect the operation of the t-stat.
FAA A&P mechanic, ex-RV dealer parts dept
Retired B-52 Gunner/Flight Examiner, B-52 Crew Chief
2016 Jayco Eagle HT 29.5 FBDS w/ 15,000 BTU AC, 50 amp service, upgraded counter top, thermal pane windows, elec. stab jacks, outside grill, backup camera and MORryde pin box.
2011 GMC 2500HD DURAMAX/ ALLISON