basebox 2 no power supply on connecting with my 450g

when i connect my basebox2 with pc lan port it connects and responds to winbox… But when i connect same to any other modem or my 450g it disconnect power supply.

scenario
when i connect poe lan port to any modem or my 450g no power @ basebox2 and poe light off.
when i connect poe lan port to my pc lan port every thing is fine and accessible tried to bridge pc lan port with usb wifi modem to shair internet works fine.
*tried reset
*updated latest OS
unable to use my basebox2 with my routerboard450g…

Plz help