This works as designed, the management access to WAN port is disabled for security reason. If you are sure that you really need this you can enable WAN access in the Security section.
In the top message you stated that "I cant access vbpe web page via wan address but lan ip is working fine" and there was no one word about connection problem.
As the issue can be caused by the defective hardware it will be a good idea to contact Polycom support team.
Sounds like a dead port...
I would try some last things:
Since you can access the VBP from the LAN port try using the Network Test Tools to do some basic troubleshooting.
and I have not tried it but you may be able to use another lan port through setting up WAN Link Redundancy... (maybe worth trying)
Thanks for the comment. I can log in vbpe webpage via lan port. The wan port status shown on the admin page is "no link" but the wan port has flashing green light.
According to polycom vbp 5300 lf2 hardware guideline, the act led flashs in green light means "The adapter is sending and receiving network data. The frequency of the flashing varies with the amount of data being transferred."
the speed light is off while ack led flashs green means "the system operating at 10 Mbps " so i thinks the port may still work
however i have no idea how to fix this.
It's a crazy idea but try to go through the different modes of WAN port in System -> Set Link section.