In the past few weeks, there have been a number of fixes/installs where installers have reported slow speed tests from the router, followed the connection, and found that the Gigabit PoE plugged into the ePMP radio is what is causing the issue. Every time, they have fixed the issue by replacing the Gigabit PoE with one of the 100 Meg PoEs. Another interesting thing to note, is that according to our head tech, each issue with the gig PoE has occurred when the PoE is nearby or resting on top of nearby electrical devices (in one case it was a UPS, in another case a subwoofer. Maybe coincidence, but I can't say). Specifically, the reported issue is that the download speed gets throttled down to 1 mbps or less, while the upload is unaffected. Has anybody else had a similar issue with the Gigabit PoEs? Do we just have a bad batch mixed in?
We are having the same issue as well, in very similar situations. We even had one that was caused by a UPS and one that was caused by a sub-woofer. The third was caused by several romex wires going by about 18" from the PoE. Here is how Cambium support responded to it:
"Solution/Suggestion Provided: That is true, when two power sources are kept near by then there may be EMF(Electro Magnetic field) occurs which may cause interference with the other one. So that, the speed of the Ethernet port may goes down. Yes, the 100mbps & 1gig POE adaptor hardware are different. Since its a 1gig port, it take very less time to pass more data. So, when there is an interference for less time will highly affect the speed. However, for the same amount of time when 100mbps POE adaptor is used, the speed is affected much. I hope this information is helpful and clear for you".
While that is true, I have never seen this with any other 1 gig PoE's even in small cabinets on AP sites with UPS, multiple PoE's, incoming 120 volt wiring, etc. I have never seen it with the ePMP 1 gig PoE's until the last few weeks. I suspect it is a bad patch of PoE's but that is not confirmed by Cambium at this point.
There suggestion so far is to put the PoE far away from EMF sources like UPS units. Most clients who have a UPS want the PoE plugged into it so that their internet stays up with their computer.
This is a recent problem, not something that is "normal" and needs to be addressed.