I personnaly chosen to send back that router. I have tested another one (other brand), and it work just fine, and even in AC mode the results are better with the new one. I'm sorry for TP-Link, but...

@oursoul It's not because a CPU has less core that it make it a weakest processor. Things do not work like that. In fact the intel CPU has some features that allow it to work faster with network card...

Honestly.... none of them. There is Wifi 6 (AX) routers in the same price range in others brands. (I won't give names here by respect for the TP-Link forum) Trust us, don't do that, it's a bad idea....

I do have the exact same issue with the AX50/AX3000. It work fine in AC mode, but I get stuttering when I turn on AX mode on my router. I heard that it came from the Intel CPU in the AX50, but...