Server changed to a new datacenter. Now purchase button for new members are not working.

My server has changed to a new data center and after that we started experiencing the time out issue with Membership 2. The only difference between the two servers is that the old server was running PHP 5.5 and the new server is running PHP 5.6.

The issue started appearing after being moved to the new data center, no other change was applied and Membership was working fine before that.