Router just pauses (stops working) intermittently

Through some painstaking trial and error, the problem has to be internal to the router.

I have about 50 different devices on my network mixed between wired and wireless.

I blocked all wireless devices... still had the problem.

I kicked everything off wired except for my laptop... still had the problem.

Disabled the wireless... fixed the problem.

So it's a wireless issue.

I have an old Cisco AP that I spun up, connected to the R8000, and started connecting all my wireless devices to the AP.

Currently I have all wireless devices connected to the AP (which is connected to the R8000), all wired devices are back online, and no problems.

If I enable wireless on the R8000, it pauses every 30 seconds.

Even if I rename the SSID so nothing connects to it, I get the pauses.

Next steps:

I'll do the downgrade and see if that helps.

At one point I was running the pre-Armor firmware and wasn't budging but the security fixes were too enticing.

To answer some questions:

No... I do not have cascaded NAT.

I have to use my ISP's gateway/router.

I have a static IP set up in the ISP's DMZ for the R8000.

I test by pinging the internal IP of the router.