YHM TI question

[TCB]

I noticed a "star" pattern on the end of my YHM TI today after shooting a few rounds of 7mag. There doesn't appear to be any baffle hits but I haven't seen the markings before. They're the faint blueish colored marks in the pic.

Any idea what would have caused it? Any reason for concern?

[TX03RUBI]

Just fouling. It’s natural when the gasses expel themselves.