I've never seen the marks on the shield cause a problem. I just hit with a coring tool to get a new bevel and replace the connector unless like was stated early the center conductor is discolored. If it is I cut it out, step back 3 or 4 feet and put a SS and new connector. The problem goes away probably because when you hit it it's making a good connection again. The old connectors have probably been there for years summers, winters they are like me just old. Good luck.
Life is what happens while you're busy making other plans
This is CABL.com posting #327802. Tiny Link: cabl.co/mbxri