Well, AI Roaming setting and DTIM setting had no positive effect on reboots. The AP went 75 minutes then rebooted. Then just 15 minutes later, it rebooted again.

So now I've disabled Fast Roaming entirely (making it a lot like stand-alone mode). Let's see if that helps the reboot situation (while thoroughly compromising the entire point of buying a managed AP).

I've powered the AP with both the 12V adapter that came with it as well as POE so I don't think it is losing power.

The AP stayed up for over 2 days on firmware v1.0.5 (what the new one shipped with a couple days ago). I then allowed Omada controller to update to the latest firmware (v1.1.1) to gain the Mesh function. That is when the reboots started--when firmware was updated to v1.1.1.

The AP itself is rebooting, as it drops all clients, drops connection to a mesh node, then reconnects to everything and the uptime counter resets to 0:00:00. The event log shows the device re-acquiring an IP via DHCP.

And it isn't because of mesh, because I now have nothing meshed with it. Instead, I am using an EAP245 with no clients as the mesh root --just trying to troubleshoot the EAP660 HD, which reboots more often as the client load goes up. In stand-alone, it runs for days with no issues.

Short cables have been tested--no changed.

Disabling fast roaming did not work.

Support recommended turning down the WiFi power to Low on 2.4GHz and 5GHz. The AP has been up now for 27 hours, no reboots. Looks like an over-heat issue?

I've used the 12V power adapter that came with it as well as POE. This has happened with a 13 month old unit and its 12v adapter and a brand new unit with its 12v adapter, as well as POE.

I do think it is thermal (we can agree to disagree) since the reboot frequency seems to be determined by the client load/count and power output, and thus heat generated. If it was voltage related, I would not expect the reboot frequency to be on the order of hours and somewhat random when load is reduced, nor would I expect it to be 6 to 10 minutes , but again random, under heavier load.

Regardless, there appears to be clear issue where the device cannot stay up for more than 6 minutes (at times) under load of only 15 clients, when managed by Omada and running at full radio power. In other words, when used exactly as advertised for its intended use, the device is not stable.

Consider that the product page lists this for use in a shopping mall or rail station where there would be more than the 15 clients present in my environment, most of which are older 1x1 802.11ac or 802.11n STAs. In a high density environment, there will be many of the latest phones: Galaxy S series and iPhones, which are 2x2 clients on the 802.11ax standard (faster data rates--more energy and heat), which would be even more taxing than the four 2x2 ax clients I present.