There is a bright spot in the photo.

Wipe with a cotton swab dipped in medical alcohol, and then wipe with a dry cotton swab.

What kind of absorbent cotton is a cotton swab? In addition, you should prepare something called deerskin (actually, it's not, it's better than it, I forgot to see anything).

If a black object has a reflection point, if you don't measure at the reflection point, you will have a so-called light spot, which is normal.