Truck Side Rails I Have Bed Rail Caps On My Truck. The One On My Driver's Side Will Not Stay Attached To The Bed.?

I have bed rail caps on my truck. The one on my driver's side will not stay attached to the bed.? - truck side rails

I tried to screw with silicone, then, but I did not live because there crap and I am very proud of in my car, it seems. I try to repair it without having to buy me a new game, so that if someone an idea, then I would be very happy. Thank you for your help.