I have a 2910, 2610 and 5406 switch that I tried with all of these and still have the same issue.
I have not mounted in the ceiling as yet due to this issue so I just have them where I can access AC power until I can figure if it's a switch firmwar...
I am having this exact same issue with all of my POE switches. Only solution I found was to add external power to the AP for about 5 seconds and then remove and the devices would stay powered. Not the perfect solution but worked for what I needed tod...
