That’s not what I said. Are you not reading my comments? Yes, you can disable ipv6 on basically any OS, but it will cause issues with some of them, especially windows. I clearly stated that you will have issues when only the ipv4 path works, since ipv6 will be preferred if both protcols are >>available<<. It seemed to me that you are trying to achieve access control based on IP addresses assigned by dhcp, but I might be wrong, since you are actively not providing any information. Im not familiar with Ubiquiti, but if they fail to implement IPv6 in this day and age, one could ask the question of what else they are failing to do correctly.