Optic keeps coming loose on Dagger slide. ???

I have a Palmetto State Armory (PSA) Dagger slide, with an “RMR cut,” and I’m having problems with optics coming loose. This is primarily for use as a dry fire gun, but I plan to use it as a spare, at classes and competitions, in case there is a problem with my primary gun.

I have mounted/remounted a Holosun 407 four times. Twice using PSA provided screws, once using screws from Holosun, and once using screws I sourced from McMaster. Each time the screws have started to back out after less than 100 rounds, and usually less than 50 rounds.

I cleaned/decreased with acetone, then used Loctite 243 on the threads, and the last three times on the head. After 24 hours of curing I’ve done the paint “staking” of the screw head, a la C&H PWS, and after another 24 hours of drying/curing time, applied witness marks, and finally, after another 24 hours, for everything to dry/cure, I then went out to zero the optic. I also use E6000, a la @JCN. Everything is torqued down to 15 in-lb, using a Fix-It-Sticks Mini All-In-One Torque Driver.

Basically, I’m following the procedures from @SoCalDep, with the addition of the E6000, as recommended by JCN.

I’ve done the same, three times, on a Glock MOS slide. The first time with the MOS plate, and a Vortex Venom, but no E6000, and the last two times with a C&H PWS plate, with a Holosun 507, and a 507Comp. All three times, I fired over a thousand rounds, with no backing out of screws.

I suspect there is something wrong with the PSA slide, rather than my mounting procedures, because I am not having problems on the MOS slide, despite using the same mounting procedures on both.

Is there something I’m missing, or should I contact PSA customer service about the problem?