@sugar0 

To allow access to your AP for a particular device (described by its MAC address) you should use Allow filtering rule as bellow:

You have to add all device that should have access to the AP. If you leave this table empty no device that can access your AP at all.

If you don't see the "Add New" button try with another browser or check the AP operation mode - this function is not available when the operation mode is set to Client.

  @sugar0 

On AX72 Pro you should use Access Control with the same purpose:

  @sugar0 

Yes, that implies all devices that are not in the router allow list would not have access to its LAN or internet.

This works just like the wireless MAC filtering but includes also any wired devices as well.

Actually that's pretty much expected - when wireless MAC filtering blocks access to your wireless network, it would block the internet access for this device as well.

sugar0 wrote

I should add that my goal is to let only certain devices to connect to the main router like the other 3 AP's that i have around the house. One tplink that has mac filtering and 2x Asus that have the feature aswell. Only this router miss this feature

  @sugar0 

You can restrict which devices can access your AX72Pro WebGUI like this: