RV180W blocks port 80 from outside to my DMZ web server

[jeanlikethis]

Hello

I am using a RV180W router and had setup  a web server in LAN. 

I used DMZ to expose the web server so IP from outside could access my web server. This used to work fine. 

However, recently, I found outside IP could not visit my web server and always report a "This webpage is not available". At the same time, the web server could be accessed from LAN. 

I also checked the SSH port and it is OK to visit SSH server (same as my web server) through DMZ from outside. Only http visit is disable for some reason.

I updated the firmware to be the latest one: 1.0.5.4.  And also reset the RV180W many times. The problem persists. 

Could someone please help me in this case, thanks. 

Jean

[jeanlikethis]

Forget to say I also tried the :Port Forwarding function and it is not working either. 

I setup all port 80 visit from outside to be forwarded to 80 of my LAN web server and still can't make it work.

Follow up: I also tried to set up DMZ host to be the static IP, and no luck at all.

Follow up: After a port checking, it turns our the port 80 is closed. How could this be? 

Follow up: I used a different router and the DMZ works and my webserver is alive from outside.

Thanks.

Jean