Will not stay fastened! - Evolution Gun Works Trijicon RMR Sight Mount

I purchased the EGW mount for a Tanfoglio witness elite match 10mm. I used lock tight in both the set screw and the dovetail. After 20 rounds the mount came loose and I was able to slide it off. I took my slide and had it dimpled in hopes that would solve the problem, sadly it worked loose within 20 rounds. Unfortunately I was unable to return it because I lost the little cardboard insert that came in the package. Not saying all there mounts are bad. Just wasn’t pleased with my particular application.