I have a lot of old beat up ones, soo get to see these problems & play with them, not worrying about damage as much a a new one or nice old one....
Much more likely it's the lid, not impossible it's the bowl.................. You can, gently flex them by "bear hugging" either, if you're able to determine where it's flexed or out of round......
I've been thinking on how best to test for round / flatness / matchup & haven't come up with anything foolproof yet.......tried a level a on a board, but it does really tell the whole tale........just done it by spending some time studying from all angles......
***For a new one, I'd wait to hear back from Weber 1st