LGA 1700 standoff broken

[Rythmer]

Hey all.

I installed the H150i Elite LCD for a 12900k. I finger tightened opposite corners and used a screwdriver to slowly and carefully snug them up.
All corners seemed to bottom out before they got very tight.  However, one post started to get tight and I stopped, but it didn't bottom out.
After doing some benchmarking and heat monitoring, I didn't like the fluctuations of temperatures and checked the screws again.  This time the one that got tight but didn't bottom out continued to turn with a screwdriver and just fell off.  The standoff threaded part seemed to have twisted off inside the thumbscrew.  And just to clarify, I did not put much pressure on these.  It seems like this may have been a bad standoff? I've ordered another standoff set because I don't know if I got a bad batch or if was maybe a bad standoff. Has anyone else experienced this?