Unfortunately the power gear manuals don't have any information about the lock mechanism.
And yes, I am positive it is locked. I can see the locking arm in place.
From doing more research, it looks like the lock may actually be made by HWH even though the slide out is power gear.
I JUST tried again. No luck. Then I flipped the battery disconnect switch off and then back on. I tried again and still nothing. Then I hit the "retract" button, I heard the motor try to move for a split second. I have done the numerous times before, but for some reason after doing it this time I was able to get the unlock button to work.
In the past I have had to push the retract button before the unlock button would work even though the slide was already fully retracted. For the past couple of days, this hasn't helped, however. I'm not sure if flipped the battery switch is what did the trick or if it was just being moody, but it worked today.
So for now, all is well......until the next time it isn't. :)