As described earlier, you can just change the GPIO lines of the RTL8231 to input one-by-one. Or just test line 10 first.
Go to /sys/class/gpio and check that gpiochip536 points to the RTL8231 (ls -l should make this clear). To export for example gpio10 on the RTL8231, you can then run (536 + 10 = 546):
echo 546 > export
cat gpio546/direction # most likely "out"
echo in > gpio546/direction # change to input, the old behaviour
Wait a few seconds and your PoE device(s) should be powered again if you found the correct GPIO.