I would also say especially different mobo and bios settings!! And of course GPUs as well.There are so many variables. Navic running a 3600, fabio running a 3900X, so two very different processors with very different TDPs. One would think that, if a 120mm AIO is ok on a 3900X, then it should be more than adequate on a 3600, but it appears that isn't the case. Different programs to stress the CPU. Just to name a couple. (I'm sure they're also using different mobo's, vid cards, etc etc etc. Different ambient temps etc etc)
I should try with an open GPU card, like the 2070 Super that exhaust the hot air through the radiator.