Look for corresponding damage/wear on the flywheel. If you have a manual transmission, look at the edge of the pressure plate and see what looks worn. Bottom line, that looks like rotational wear so I’d look at the only thing(s) rotating there and find what the damage is.

The odd thing is that it’s even happening at all. Something obviously isn’t right as far as how it’s positioned. Find what’s worn and we can go from there.

 

Pretty sure its gonna be the flexplate.

 

My guess is a torque converter bolt backing out. With the starter out mark the flex plate or torque converter with a felt pen and rotate once using a pry bar on the ring gear teeth to inspect the bolts. Might pay to check torque on each as you go regardless.