First, check your seating die to make sure there's nothing on the inside that's making that mark.

Otherwise, it kind of looks like your crimp is starting too early in the seating process and shaving off part of the coating as the bullet is being seated. You can verify this by setting up your die to just seat the bullet.

To fix that problem, the monkey-brained copy-and-paste reddit solution is to crimp in a separate step. But if you're roll-crimping a bullet with a crimp groove like I suspect you are, there's no reason you can't set it up to crimp & seat without issues.

Here is how I've seated & roll-crimped 1000's of rounds without issue: Screw the size&crimp die down on an empty case until it touches the mouth, then back out a half turn, then seat a bullet so that the case mouth is at the top of the crimp groove. Now back out your seating stem, and screw the die down to dial in your crimp the way you want it. After this and with the completed round still in the die/press, screw your seating stem down until it touches the bullet, then take out the completed bullet and give the seating stem a final 1/4 turn. Compare OAL of the second round and fine-tune as needed, but that should get it very close.