Cisco AP PoE issue

I'm sure there are other or better places to ask this, I tried on the irc but would like a second opinion. We as a business don't use much Cisco equipment currently, so I don't have much experience with it, but the hardware choice is out of my hands

Currently we are trying to setup wireless aps (aironet 1562e) over poe (poe+ in this case, so 25/30W) but they are not all drawing enough power to turn on the radios. It is not consistent between Aps either. The ones that do not get enough power log "waiting for poe negotiation to complete" but connect to the wlc (2504) without an issue and get network info etc, they just aren't putting out a signal because of low power. Cdp entries show the local host as not having any info on power_* attributes on the failing ones but these are present on the one the has radio up. Is manually setting the cdp info viable?

I have tried unmanaged 802.3at switches with enough budget to run 4 at 30W each, but even if there is just a single one it does not get the power. We also have tried regular power injectors (air-pwrinj6) as listed compatible in the ap data sheets, but even then the ap only gets 15W after waiting for negotiation.

All devices are brand new too. Currently 1 of 4 ap gets the correct power, the others refuse to negotiate it, and I have several more in boxes to setup.

I don't know what else to try at this point, we have gone through several updates on the wlc&ap to no avail. I wish I knew more before getting dumped on this. Any assistance or advice would be greatly appreciated. If we just need to return the devices under the presumption that they are bad, that's really unfortunate but it is what it is. Thank you.