ATX1800 - Set to extender mode, device doesn't appear under router

I set my ATX1800 as an extender so it doesn’t do another NAT. Now my devices are sharing the same IP (192.168.50.*)

But the two devices I have connected via ATX1800 don’t appear under the list of devices when I login to my actual router, only the ATX1800 does.

This is what I am trying to do right now (timestamped video). Is this possible to do even when my device (connected via ethernet to the ATX1800) doesn’t appear under my router?

Do the two devices got valid IP from your main router 192.168.50.x?

If yes then it seems a problem of your main router to list clients.

I don’t follow the video though.