@bk_61, as indicated in the thread I linked you to earlier, every cut must have a collar.

Since in some sources, like this one, the person in the image may have a longer neck or a lower collar than usual, this would be quite difficult to achieve naturally. This video displays a simple technique of how to cut close to the chin and still display a bit of the collar:
 

I'll fix this one myself, but please keep the above in mind for future cuts 👍