“It is very likely that a communication from a client which has 867Mbps rate could easily be “intercepted” or “lowered” by another client which is transmitting 6Mbps on the very same channel that the high-rate client operates. So, in this case, the high rate client or the AP will be affected by this low rate client, but the question is how much?”
Here are the details: Measuring the Effects of WiFi Low Rate Transmissions on the High Rate WiFi Traffic in the Same Frequency – updated Oct 2018
Oguzhan EREN, CWNE#266