@pirate 

Please provide more details about the Access Control and Parental Control issue you are experiencing, as we haven't heard about the issue before. Do you remember the previous version of the AX6000 before the firmware update? You can try to reset it to factory defaults either by pressing the RESET button or doing factory defaults via its web interface page, then reconfigure it from scratch to check again if the Access Control and Parental Control will work properly again.

Meanwhile, I wonder if there is "MAC address randomization" or "Private MAC address" enabled on the phones or Windows PCs, if it is, it will change its MAC address every time it connects to the network, you will have no way to block it. For Apple iOS devices you can find some information here: https://support.apple.com/en-us/HT211227.