Access Control blocking 1 device and unable to change to allow

This is an older thread, but hopefully will help someone. After several different approaches, I believe I've finally figured out this issue. Turns out, the older Genie software has an Allowed Device quantity limit, which includes both connected and unconnected devices. Once you reach that limit, the software will not Allow any other devices (ie, added to that list). Inane in today's age of wireless everything, but (almost) understandable when Genie was written.

The work-around solution is to clear out any outdated devices from your Unconnected listings - a list which simply grows and gets forgotten throughout the life of the router. Clear up 5 entries, gain 5 more entries for the Allow list. If you reach a point where you hit another "Blocked" device that can't flip over to "Allowed," you'll need to delete some more (hopefully) outdated devices. If you run out of Unconnected Devices to delete from the list and are still facing this issue, it's a sign that you need a newer router.

I've since swapped to a newer device that does not run on Genie. But, for those that might still need these routers, I hope this helps resolve the issue.