did you try to check the Port1 PoE In Long Cable and apply? i was trying to power with 260gsp (with power on port1, no jack) only one sxt (port5) and it did not work, so i check the Port1 PoE In Long Cable apply and suddenly its working well...Today i tried to power an RB260GSP in poe port1 and power 3 radios, it didn't worked. The radios power compsuntion is 3.665W 3.034W 3.385W. PoE Current 153mA 133mA 142mA. So it cant provide 500mA total on 3 ports.
It only worked with DC jack.