Update: I picked up some 5/8 inch cinch clamps off amazon and decided to try them out on a shut off valve I want to install on my toilet first as it is easier to reach. I cut the line and immediately noticed the ID of the tubing was not the same as what I bought from Ace, seemed a little larger, and the OD slightly smaller. I put the 5/8 cinch clamp on, clamped it down on the ball valve and it fell off lol. I tried the 1/2 clamp and it was something else to get on but eventually was able to and good to go.
There must be some different type of tubing than what I bought that FR used because I will never get a 1/2 clamp on this tubing I purchased, even though both are 1/2 inch ID PVC. My search continues for similar tubing. I have bought two different brands now.