I had a problem with SA modules, it was actually the housings were slightly out of spec. When you would tighten the module all the way it would warp slightly. We showed the SA rep this in the field at the affected locations. This issue was back in the 90s in MA with Continental Cablevision.
You don't always get what you expect, but you know what you got when you inspect. Happiness comes from within, some poor souls are just without.
This is CABL.com posting #138196. Tiny Link: cabl.co/mJ68