|Hard to understand what you are saying. Statements like this are contrary "This IP we are configure our own dynamic site" Do you mean web site? I never have heard of a "dynamic site".|
Not sure what you mean by dynamic ip [dhcp provided ip] in relation to your web site nor is it clear where it works and where it doesn't.
How about trying again with specific information like;
did your wan ip change?
is forwarding setup in your router for your web server?
did your web servers static ip get changed?
if web access works with a dynamic ip from both internal and external, is this a problem and why?