Check Rollers
We have a 2019 Thor Aria 4000. Super slide got stuck in same spot similar to yours. Seems the rollers on the bottom of slide were not making contact with the slide and floor. The weight was all on the side tracks. That's not good. I had to replace all the side tracks and the rollers needed to have a shim to make a good contact and carry more of the weight. After $5000.00 it runs perfectly.
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