GS310TP PoE seems administratively disabled, with no way to re-enable

 After I'd been happily running this switch with a Cisco WAP plugged into it for PoE, I saw there was a firmware upgrade available, so I went to check it out. (Yes, this may have been my mistake.) Upgraded from 1.0.0.10 to 1.0.1.2. And suddenly, the WAP was dead. Tried a new cable, then a few more cables, just to be sure it wasn't that easy. After much fiddling around with the bits of PoE config I could alter, including trying every possible combination of Power Mode & Detection Type, I'm coming around to the idea that it's this setting (sort of) in the overall PoE Configuration, rather than the specific settings in PoE Port Configuration. There are three configurable settings there, System Usage Threshold, Power Management Mode, & Traps. But there's also been an unselectable entry, Power Status: Off, staring me in the face all along. At first, since it can't be changed there, I thought maybe it was just indicating that with nothing currently using the PoE, it wasn't providing any PoE. But having tried everything else I can think of (aside from a new PSE or PD, and I don't have another of either to help troubleshoot and make sure the problem is on the switch, rather than WAP), I'm very much wondering whether that is administratively switched off somehow, even though I'm pretty sure I never did. Oh, I've also downgraded to 1.0.0.10 again, but it's still stuck Off.

So, any suggestions? Preferably that don't involve me getting another PSE/PD for testing. If it involves SNMP, please be clear & complete about it; I don't really know SNMP well, and certainly didn't accidentally turn it off that way.