Check your devices in device manager.From desktop, right click my computer, properties, Device manager,Under that check network adapters, if you have Microsoft Virtual adapter disable that (might be more than one) and try your speed test again, post...

There has been a beta firmware for the AX1100 that had WPA3 but it was taken down (Info SNB forums) AX and AC work with one another on the 2.4 or the 5Ghz channels, I use both with no problems, AX is really fast, for gaming its amazing.Regards