Also check the forums as there are other post in regards to connecting an AP on one of the PoE ports. It’s not suggested to connect aps to the ports, but if it’s for home use or lab, I don’t see why not. Just review other post as they have suggested how they got it working. The one reason O don’t like that approach is that the ap and clients need to be on the wlc management vlan. You have better flexibility using a switch.
The issue with using the PoE port is that you have to have everything on the management vlan. The ports are not like a true switch, so you can’t have the ap on a different vlan and or put clients on a different one. That is the limitations when an ap is connected to one of those ports.