Slide out operation and maintenance

I have a 2006 Palomino Puma 30ft pull-behind with a slide-out, I believe the slide-out is a screw drive type driven with a 12v electric motor. I'm not sure if the slide-out is operating normally, I have noticed that when it is fully extended the rail seems to push out the bottom of the slide-out wall a bit so it's extended further than the top of the slide out, and when I retract it the top seals up first and then the bottom still has to pull in a bit causing the whole room to tilt and flex slightly as the bottom seals up. I also noticed that the room doesn't seem to slide smoothly but rather it pauses with a jerky motion occasionally.

I just got this camper and plan to do some maintenance and just wondering if that slide-out behavior is normal?

Also, I do plan to get some dry lubricant for the slide mechanism (Protect All Slide-Out Dry Lube Protectant from Camping World) to address the jerky motion, unless there is something better to use for that?

Thank you!