Next time you are experiencing the problem, leave the ignition in the ON position. Go outside to the G6A panel, typically in the electrical bay under the drivers seat (on DP Class A's) Check that the Green Slide LED is steadily lit. If it is, then the safety interlock (Ignition On and Parking Brake ON) are both working. If Not, then those signals are not getting to the Board in the G6A panel, or they are potentially intermittent. Then the hunt for the problem would begin.
How old are your coach batteries? How low a voltage are the batteries dipping to when you try to activate the slides. This would probably be my 1st guess. Especially if the frequency, and extent (more items becoming intermittent), of the problem has been increasing with time.
Where we started back in '82. When cheap beer was good enough.
The Force is being built.
2019 Jeep KL (Cherokee) TOAD