RT-AC87R - 2.4 GHz Network AWOL

I have an Asus RT-AC87R and yesterday I had 2.4 Ghz and a 5 Ghz bands working perfectly. Today, my 2.4 GHz connection is gone and cannot be seen on multiple devices. I have rebooted the router, performed a factory reset and reinstalled my network adapter. I have also confirmed the 2.4 GHz is broadcasting and active.

Windows 10 64 bit
Intel AC-7260 NIC card
RT-AC87R

No matter what I do, I can no longer see the 2.4 GHz connection on any devices. I need help resolving this issue.

Thanks.