Randomly missing sounds has been a problem in Apex from the start, but 1) it's not consistent and pretty rare, 2) it has nothing to do with this topic about positioning of sounds. If OP can't tell direction of sounds even remotely correctly then that's definitely a problem on his end, since I have no problem telling at least general direction of sounds, even if it's not as precise as in PubG (but that one has it's own set of different problems).
Using 7.1 simulation can completely mask sound directionality. Using sound compression significantly hinders ability to tell distance from loudness. Those 2 options should always be turned off for BR games. Just a couple of potential errors on user side (apart from the obvious already mentioned terrible headhpone problem).
P.S. I use HyperX Cloud II's, which are really pretty bad headphones in terms of sound quality and the sound stage is not great, but still work well enough for sound positioning. They also have "7.1" option - tried that once - that was a horrible experience I don't want to even think about XD.
P.P.S. As weird as it sounds, I know some headphones are not even Stereo, but mono. Obviously telling sound direction on such headphones would be physically impossible. I guess there are windows setting that could also turn the output to mono and maybe broken headphones may (I dunno) fail to produce stereo output. If turning around near a constant sound makes absolutely no difference at all - a mono output may be the most likely source of problem.