@R1D2 

Is the mains power stable?

- Yes

What cable do you use between PoE injector and EAP110-Outdoor?

- I tried different cables, first using a longer 30meter cable running underground from the house. The PoE injector in-house. Then tried moving the PoE injector behind the 30m cable and used a short molded UTP cable. This cable has the ground connected, I tested this with a cable tester. The wall-outlet for the power is grounded as well.

Did you properly ground the EAP110-Outdoor?

- I did not connect the ground connector on the device, since it should be properly grounded through the PoE injector. I did test on 2 different power outlets, one inside the house and one outside the house. No difference.

To me it looks like the PoE injector doesn't provide enough power for high loads, but that is just a wild guess.

@R1D2 I did some more testing. I noticed that the access point only supports IEEE 802.11n/g/b. The laptop I use for testing supports IEEE 802.11a/b/g/n/ac. Just as a test I forced my laptop to only use IEEE 802.11n/g/b. This seems to make it more stable, no crashes after one hour of running speedtests in a loop. From what I understand this should not make any difference. The standards are backwards compatible and a wifi signal should never restart a device. What are your thoughts about this?

Edit: never mind, it crashed. Turning off QoS seem to have a great impact on stability though. But without QoS the speed dropped from 80+Mb/s to 10Mbs. The cpu usage of the access point is lowered as well.

@Fae I use the PoE adapter provided by the device. The EAP is not managed by Omada controller, but used stand alone. It will not reset to factory settings, only the clock is reset to the default and the log is cleared. There is only one client connected during test, so yes.

@Fae 

Do you mean the EAP still keep the customized SSID after you try resetting it? How did you reset it?

I do not reset manually. When the EAP is on heavy load (speedtest), it restarts (reboot). It keeps the custom SSID and the password. Only the date/time is reset to 2014 and the log is cleared with 2 default entries. To me this is strange, because it looks like a partial factory reset, but not compete.

If you can access the web management page of the EAP, please reset it from the web UI.

Or press the reset hole for about 8 seconds when the EAP is powered on.

How to judge it is reset successfully:

the LED status would flash green-red-yellow and then default SSID would show up once it's restarted.

I did try to reset (not restart, but factory settings). That resets the SSID. My issue is not the resetting, but I don't want it to restart (reboot) very often.

If there is another 24V PoE injector available, swap and test whether it's the PoE issue.

Unfortunally no, I did test different cables.

If no other POE injector for test, but the issue still exists, you may contact the reseller for a warranty replacement.

Ok, I will do this.

I wish there was a way to test this and 'proof' that the POE injector is the problem. As an IT-professional, I like to thoubleshoot before replacing.