How can I correct a gap between joists and a beam on a new construction deck?

I am building a new deck. It’s a basic 16′ by 20′. I installed the posts, ledger, and 2 beams. I am working on the joists. When I hung the joist hangers, I didn’t check their contact with the beams from the joists, just for level. Now that all of the joist hangers are hung, some of the joists don’t make contact with the center beam. Some of them are off by nearly 1/4".

I know I can pull the joist hangers off and install new ones slightly lower to solve the issue, but I’m trying to avoid that.

I thought about shimming under the joists but I didn’t think that would be structurally sound.

Is there a way to fix this without having to take down the joist hangers or the outer beam?