Well, it seems to be about the shelf. What about the leading edges of the quills? Are they smooth? Are these newer fletched arrows?
I like to smooth mine down with a file or you can burnish down and dab a little glue on. I've shot selfbows for quite awhile, and had the same happen, time to time. Usually a sharp quill, 3 or 4 fletch!
I have shot lately with the cheap mechanics gloves from dollar store, work real good. Maybe your gripping a little higher than norm?
You didn't say, is the arrow flight good? If so, put some super glue on the raw meat, and get shootin!
Good shootin,
Steve