PC’s do NOT get the updates from WSUS 3

Hi,

Thanks in advance for reading my question!

I had WSUS 2 and was working fine. all pc’s used to get the updates. recently, i have upgraded to WSUS 3 with the same port numbers.

the computers dont seem to get the updates. i have checked the port numbers on WSUS 3 and desktops (Group Policy) and seemed to be correct.

I dont know what is going wrong?
Could you please help?
Thanks