disconnect the power cord then disconnect the battery, let it sit 30 seconds then reconnect everything. My guess is the system needs to be cold started to reset it. Your not the first person to have issue like this. I think if you use the hydraulic pump for the landing gear or the slides without shore power or the truck running can connected it see low voltage and caused it to lock up.
Mark & Melissa
2015 Redwood RL38 , Kodiak disk brakes , 17.5" tires , 8K Morryde IS