@d0ugmac1 

My PC is actually plugged into the POE injector. I have it this way because even when it was connected into one of the ethernet ports on the AP, the problem persisted. I shall test once more just to make sure. 

Returning to this thread because the issue is still happening

My EAP 615 is downstairs on wireless backhaul, works perfectly fine when it is first adopted but the moment I reboot the AP the speeds go to 10mbps and .09 upload on a normal google speed test.

The AP and PC are both connected to a TP Link POE injector TL-POE160S

Here is the uplink info for the AP. Nothing seems to be wrong. The exact same issue is happening on not one but two separate EAP615 Wall units. 

When I reboot the AP again, my TX rate drops to 288.

I also generally keps the WLANs off because I"m using this AP solely as a method of wiring various devices into the POE injector however when I enabled the 5ghz band I see this:

I may have fixed my own problem?

On the AP settings under WLAN, what do these toggles mean? Do you turn them on so that the AP also broadcasts the networks? Or is it something else?

I ask because I initially had them all turned off because I was using the AP as a glorified wireless adapter for devices that didn't have built in Wifi 6. All the issues that I summarized above were happening but the moment I turned all of my networks on in the WLAN section, the AP started to give full speeds in network tests again. What do those on/off buttons do in the WLAN page and why does it affect the WIRED speeds from my AP? By keeping all of my WLANs turned of, was the AP at reboot not officially connecting to any of those networks?

Then the related question would be how do I still utilize the AP as a delivery mechanism to convert wireless into a cable but not broadcast any of the networks from the AP itself?

I have so many questions haha. Thanks in advane for any guidance. 

  @d0ugmac1 

My finding yesterday was that when I go to devices - click on the AP - config - WLAN - 

Here I thought was where I choose what SSIDs the AP broadcasts. In my case I didn't want it to broadcast any SSIDs which is slightly strange but as I mentioned it before I was mainly using the AP as z means for clients to physically wire in. When I turned all of the WLANs off then reboot, the AP speeds would turn into doodoo at extremely low download and upload speeds, also showing the 5ghz band as 94% utilized for some reason. 

  @d0ugmac1 

Yeah I know my use case is a bit strange but I think using an AP as an Ethernet endpoint is an underutilized option. My problems have fully gone away as soon as I turned on all of my networks in the VLAN section of the AP config. To recreate, just turn them all off, reboot the AP, then run a speed test. My device is an EAP615 WALL to be exact.