I would try to get some education in how to "tune up" your slide. Or, if the floor is level but the table is off it could be more of a woodworkers project to get it level. Youtubes on every kind of RV repair are helpful if you look at enough to find a reasonable solution to your problem.
I searched "how to level a slide out on rv" and several to read or watch.
If you find the problem and solution but think it is a dealer type work than take it to them with both the problem and how you wanted it solved. They may now know how or just lazy.
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6