Asus TUF Gaming AX3000 V2 Dual Band WiFi 6 Router Issues

[Bellows]

hi, as title says.
basically what i don't understand is in router settings connected devices every day my son starts his pc the same PC NAME is always displayed but the mac address is different to no matter what rules i try to setup nothing works, here is what Ive copied from router settings DESKTOP-FILM059 MAC address 00:11:A7:93:CB:68/DESKTOP-FILM059 MAC address 02:C0:57:07:F9:34/DESKTOP-FILM059 MAC address 02:26:1D:0E:35D.
can any 1 explain whats going on, cheers
his OS is WIN 10 latest build

 

[Bellows]

its all for setting setting family filter, setting times internet comes on and goes off so he not on all night, nothing works, even if i click on connected at time and click block internet it never goes off. pointless trying to set rules if router assigning a new mac address every time pc starts, defeats the point of having a family filter built in is thers