I work for a small WISP in the UK. We use the RB951Ui-2HnD as the primary router we give customers. This model has the single PoE out on port 5. We started using this port to power the Ubiquiti NanoBeam M5's we use for the CPE side of our wireless links. We have had a consistent failure when doing so. One of two things happen, either the plug on the power supply blows with a puff of smoke or the router simply stops providing the power while otherwise continuing to work. We've switched back to using PoE injectors to power the external device and have had no issue with the router or it's plug either way.
My questions is whether they are designed so they should be able to handle this arrangement just fine. If so whether we could be doing something to cause the issue or if we are being provided with a power supply that isn't fit for purpose. I doubt the latter as the specs on the plugs check out and they seem to be standard UK model plugs designed for the kit.
Let me know if you need any further details. I can provide pictures of equipment and setups if that helps. If the router is simply not designed for that purpose that's fine. Really just trying to figure out if we need to reach out to the supplier to complain and let them know about the issue OR if we need to change our setup in some way.