@roytanck 

Hi, the parental control rules take effect on both host clients and guest clients;

For your issue, I think it might due to the change of the MAC address;

The same device will use different MAC addresses when connecting to the host network and guest network;

Due to the concern of the security, both Apple devices, and Android , Windows devices have applied for the random/private MAC address feature;

@roytanck 

Since it generates a random MAC address, so there would be a third even fourth one;

So the best way is to turn off the private message feature on the device;

And it would also help us check whether it is the private MAC address that caused this issue;

Thank you.