[Richard]

Been thinking about this.

Low fluid. Slide would not fully extend.
Draining fluid. Highly unlikely since multiple solenoids would have to be leaking for behavior to follow both salon and bedroom.

This leaves low hyd pressure as something to investigate. Two potential causes would be low voltage or ground at pump, best case. Or failing pump.

There are two relays that control pump power. A little one on the circuit boards, which triggers a bigger external relay in the front bay.

This could be the wrong track. When the rooms finally do start, are they slow? Is it extend and retract? When you said sitting for a while, after you extend them once do they then respond as you would suspect?

Just thinking out loud and in public.

First and easy diagnostic is to beg Doris to hold the button, and you check voltage at the big relay. I now you said you hear the motor run, but being a DC motor, it's oomph is controlled by the voltage.