tingling/uncomfortable feeling on the glans.

I use an extender with a vacuum cup, but every time I extend, I get a tingling and uncomfortable feeling on the head of my penis. It’s so uncomfortable that I can’t keep it on for more than 5 minutes. Am I doing something wrong? I currently use tape, but I’m wondering if there’s a better way to wrap/tape or adjust how I use the vacuum cup. Has anyone else had this problem, and how did you fix it?