Reel to bedknife contact only in middle?

Just got my first reel (earthwise 16" 7 blade). It was used and I noticed the bedknife was making way too much contact with the bedknife (it was really loud when spinning). So I adjusted it until the sides were just barely not touching the bedknife. But the middle of the reel is still touching.

How can I adjust that? There are only adjustments on the sides and I think I've got those good now. Do I just backlap it until it evens out (essentially grinding it to take shape of whatever's bent)?

I'm assuming something is bent in the middle because I don't know how else I'd only have contact in the middle on the blades. What would you guys suggest?