Yes Ralph, as Mark mentioned, maybe your screw was not of adequate size. In every modification that I did, I always used a #10 SS screw, along with a tight fitting anchor (never had one come outj.
And as for attaching the leader, I simply looped it over the head of the screw, just under the head, tightening it (the screw) down, just enough to touch the leader. And contrary to some, I wanted the leader to be free to shift around to either side, rather than being tied in place. The rubber cap will keep things from disconnecting, and with the right anchor & screw, hopefully the whole thing won’t pull out.