I see you have the same rod holders I have and are attached to the rail just as mine are attached. I have trouble with mine not getting tight enough and turning on the rail, mostly when striper hit. Have you had that problem?
I have tried to cut rubber strips and tried sand cloth. My guess is my rail might be a bit to small.
It sounds like your rail mounts are to big! Tape a soft tape and measure I believe it’s eother a 7/8 or 1 inch. Go to hills rod holders, he has the cheapest and the best rail bases by far!