I upgraded my Mikrotik Powerbox Pro to 6.42.1 due to the winbox security issue. I am not getting overload POE errors on a port that is connected to a Nanostation M2 Loco. Anyone else having this issue or can offer a fix?
Poe-out logs where added quite recently (version 6.40) - maybe you had that problem all the time but you noticed only now because of logs?
Is there other poe devices connected to your PowerBox? If total consumption reaches 2.4A (with 24V power supply) then poe-out port with lowest priority (in your case it is most likely ether5) will be powered down and overload event would be logged.
Try moving your nonostation to different poe-out port (ether2 has highest priority in default configuration) and check if problem moves with device.