AirPort Extreme Timed Access Control Issue:

I have been using AirPort Extreme (Version 7.7.8) Time Access Control functional for many years, and my settings have always been:

default = NoAccess;

IndividualDevices = Everyday+...

I gradually accumulated lots of devices on the "wireless clients" list, many of which comes and goes over the years. I typically still list them there, sometimes just change the broken devices into "NoAccess". Over the time, my list has some 90 devices.

Recently I bought a new iPhone, and I tried to add it to the list using its WIFI Address, granting it Everyday+AllDay. Yet, it wasn't able to access WIFI. So I made the default = Everyday+AllDay, and the new iPhone is able to access WIFI.

I am now revisiting the problem, and assumed the root cause might be my list being too long and above the 50 device limit of the AirPort Extreme? I scrubbed the list to remove the unused devices, and shrinked the list into ~40 devices. To my surprise, the new iPhone is still not connecting unless default changes to Everyday+AllDay. Not only that, one of my previously working iPad also changed to behave the same as the new iPhone. I double checked to make the the iPad is still listed in the device list with the correct/unchanged MAC Address... Now I am not sure what's going on wrong. All other devices seems to be fully functional as before.

There is no update on the AirPort Extreme SW, nor any update on the iPad SW.