Apple TV won’t work with ATT AIRTIES extender

My Apple TV (latest generation) connects with no problem to my AT&T (U-verse type modem) via Wifi. When I add my AIRTIES AT&T Smart Wi-Fi Extender, which uses same network name and password (like most mesh network extenders) all my other iOS devices work perfectly, including iPads iPhones etc.

But while my Apple TV shows that it is still connected to the network, it won’t function, as if there’s just zero speed or it’s not really connecting. It shows that it’s connected but it won’t work. Now I’ve tried restarting Apple TV, I disconnected from the network and then reconnected again, re-entering the password again, I have the latest software update, I’ve done every possible thing on my end. Does anybody have any ideas?

Of course when I disconnect the extender it works perfectly. So it’s a matter of somehow it is not working through this extender or when this extender is connected and up and running