access control keeps borking up

[#1]

I use access control to limit certain devices use that belong to children. For years it works some of the time, but every npow and then, after changing teh times on a device or trying to add a device it all goes a bit mad (see screenshot) these four devices were 4 different devices and now all of a sudden show as one. And I cannot add new devices either. Previous times I have done a factory reset of the router and that works, but its very annoying to have to do that as it loses all my other settings and device names.

[#2]

Does this laptop have MAC Address Randomisation enabled ?

[#3]

nope, and its nothing to do with the device itself, sometimes it will show a list of different devices. It happened this time when I tried to add an iphone. which doesn't even appear on the list as anything.

it will work fine for months with changes being made then suddenly, one change, and it all goes to pot.