Our iN-command controls is displaying our "zone" for each unit as -F. None of the units will come on. We have 2019 model and have used it two months

Please post a picture of your display panel. There are at least 4 different iN-command systems.

you may want to unplug from utility power and turn off the battery disconnect to power down and restart the electronics. Some coaches may require disconnecting the battery depending on where the InCommand head end is powered from. Just a guess but if the battery get low or any type of park electrical voltage problems can cause electronics to go crazy.

Best of luck , let us know what you find!