Since the early 1990s, I had never a single Apple factory provided RAM fail, but certainly severals from 3rd parties – in the very same machines. And, of course, I've been too greedy to pay the premium… (But, in the end-run, this has probably been more expensive and certainly more of a hassle.)
Unless you're Samsung, almost all RAM is 3rd party. It's either Sammsung, SK Hynix, or Micron.