Maybe Avid's QC is crap and you have to get lucky?
There’s always sus looking sellers doing then mega cheap on eBay etc, I dunno if they are all out fakes or the ones that get rejected at QC going out the back door. Kinda suspect the latter and that these ones are the root of much of the issues. I once bought a pair of callipers from one of these listings and one was fine, the other really lacked bite. I stripped them down and I can’t remember exactly but I found two washers where there should be one in the one that wasn’t really working.
There’s always sus looking sellers doing then mega cheap on eBay etc, I dunno if they are all out fakes or the ones that get rejected at QC going out the back door. Kinda suspect the latter and that these ones are the root of much of the issues. I once bought a pair of callipers from one of these listings and one was fine, the other really lacked bite. I stripped them down and I can’t remember exactly but I found two washers where there should be one in the one that wasn’t really working.