Funny you posted this today, I just replaced the motor for the steps on our 2014 Bounder 35K. It seems the motor has a tendency to work intermittently when it is losing interest in it's function. 

It was an easy replacement, took about 45 min in all. If at all possible and you have a voltmeter, unplug the power source that goes into the motor and check for DC voltage . If you have power present when opening and closing the screen door then it is probably your motor. If you need I can probably get you the part # off of mine. 

                       Don W

On our 2014 Bounder 36e, we also had to replace motor in 2020, it also intermittently  would not extend or retract.  Works like dream, wasn't hard to replace ourselves 

Thanks for the information.  The steps seem to be working fine now.  I have ordered a new step motor from REV.  I've replaced it before and know it is not hard.  Thanks again, Bob