[Bored&Stroked]

There seems to be issues with most of the repop lifters - especially with the screws loosening. Others have had issues with material quality and hardness. I've not yet tried the Flat Attack lifters - they appear to be very high quality and maybe they don't have these issues.

Given the problems you're having, you might consider either a thin "jamb nut" on the adjuster body or red-loctite . . . or try to compress the adjuster and get more thread interference. The last method might be a little sketchy in that it is hard to "get it right" when you don't have any spare adjusters to swap in . . . if you get it wrong.

Best of luck!
B&S