Welcome to the Winnebago Owners Community!
You did not state in your original post that the coach does not level when you operate the leveling system. So , post #2 is off topic for your issue.
On a properly working Winnebago once you level the front-back and side-side level will stay the same with slides in our out, when your jacks all deploy on solid ground and all 4 jacks make solid contact with the ground. Sometimes you have to spread out the weight with jack pads, you can buy these or by using plywood squares. I use 12" x 12" 3/4" plywood squares. You can stack the squares where jacks are over low ground to make sure they all make solid contact.
Since this is your first post some other best practice you may not be aware of:
You want to avoid using jacks to lift the rear wheels off the ground, and never on both sides. The parking brake only works on the rear axle wheels you you are less stable with rear wheels off the ground.
Buy 2 good wheel chocks and chock at least 1 wheel that is making good contact with the ground.
Drive wheels up on leveling blocks and get it within 2 degrees level side-side and front-back before you start to auto level.
If you are doing all these things and you still are having the intermittent leveling issue and can reproduce it at will on a hard surface parking lot then you have a warranty issue, chances are the hydraulic valve assembly on your leveling system has a bad seal.
Randy - Manhattan, Kansas
2015 Vista 27N
2016 Honda HR-V