It’s hard for me to tell what’s going on in the picture; is there a uniform gap all around? What’s the point of contact on the right edge?

In any case, a top cap is not needed at all after the bearing preload is set, so depending on how that was done, if this is a case of the cap not being perfectly flat, it could be a non issue.

What I’d do is just unscrew and remove the top cap, loosen everything up, add in another spacer above the stem, and reinstall the top cap and tighten the headset down appropriately. Then, I’d torque the stem bolts, remove the spacer above the stem, and replace the top cap as a cosmetic element.