I’ve been having loads of trouble with the 8.5.x firmware release - the main issue is some sort of VLAN issue described here: Outbound Policy + Firewall + VLAN bug in firmware 8.5 - #15 by soylentgreen
Yesterday, another weird issue started - one of my Peplink AP One Minis is dropping offline. The LED is Red, and the AP log shows simply “Disconnected”. It’s running on PoE and has been working great for years on the 8.4 firmware.
Before I power cycle the AP, is there any diagnostics I can do?
I realized my APs were running firmware 3.9.3. I will upgrade them to 3.9.4 and see if the problem recurs.
So far, however, I’m really not having a good time with Firmware 8.5 and 8.5.1 - I’m having so many issues that were not present with the 8.4 series. 
Upgraded to 3.9.4, and the problem is still happening.
In fact, I can now reproduce the issue:
- Connect a client to my AP One Mini on 5GHz (in this case, it’s a SteamDeck, but I don’t think that’s important)
- start a big download
- a few minutes later, the AP goes offline with a red light.
When this happens, the AP feels quite hot - these AP One Minis normally run pretty warm, as shown here:
But this feels hotter.
Also, I have 3 AP One minis, all running on PoE, but only one keeps rebooting. This is the one running on a lower power profile (7W Class 2: see my prior description )
My theory is that perhaps something in AP firmware 3.9.3 or 3.9.4 is using a little more CPU, which is increasing the power draw, and eventually the AP goes offline?
I’ll try putting this AP back on a full 12W (Class 3) PoE and see if that fixes the issue.
Indeed after more testing I’m sure the problem is not heat-related, but rather the 7W power limit on Class 2 PoE - I was able to reproduce that whenever the AP One Mini tried to use more than 7000 mW, the PoE was cut and it rebooted. Details here: AP One Mini PoE Class vs. TrendNet TPE-P521ES - #5 by soylentgreen