Some Sites Blocked

My Mikrotik allow web surfing to any site from PC behind the firewall.
HOWEVER: just one is unreachable. It is reachable from other LAN (not Mikrotik based).

PC behind MK router/firewall:

[giuseppe@godzilla ~]$ curl -v -k https://www.easyplansb.it:8443/easyplanweb/mvc/EasyPlanSB.html
* Adding handle: conn: 0x206b930
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x206b930) send_pipe: 1, recv_pipe: 0
* About to connect() to www.easyplansb.it port 8443 (#0)
*   Trying 5.196.204.34...
* Connection timed out
* Failed connect to www.easyplansb.it:8443; Connection timed out
* Closing connection 0
curl: (7) Failed connect to www.easyplansb.it:8443; Connection timed out

From other PC not behind th MK router:

giuseppe at fukuoka>curl -v -k https://www.easyplansb.it:8443/easyplanweb/mvc/EasyPlanSB.html
*   Trying 5.196.204.34...
* Connected to www.easyplansb.it (5.196.204.34) port 8443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* skipping SSL peer certificate verification
* ALPN/NPN, server did not agree to a protocol
* SSL connection using TLS_RSA_WITH_AES_128_CBC_SHA
* Server certificate:
* 	subject: CN=web.easyplansb.it,OU=Sabacom Small Business,O=Sabacom s.r.l.,L=Taranto,ST=Taranto,C=IT
* 	start date: Feb 08 14:03:28 2012 GMT
* 	expire date: Jan 15 14:03:28 2112 GMT
* 	common name: web.easyplansb.it
* 	issuer: CN=web.easyplansb.it,OU=Sabacom Small Business,O=Sabacom s.r.l.,L=Taranto,ST=Taranto,C=IT
> GET /easyplanweb/mvc/EasyPlanSB.html HTTP/1.1

Other https sites work well, e.g. from the same PC behind MK:

[giuseppe@godzilla ~]$ curl -k -v https://www.google.com
* Rebuilt URL to: https://www.google.com/
* Adding handle: conn: 0x1960840
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x1960840) send_pipe: 1, recv_pipe: 0
* About to connect() to www.google.com port 443 (#0)
*   Trying 216.58.198.4...
* Connected to www.google.com (216.58.198.4) port 443 (#0)

It would be helpful if you included the config of your router so we could see how it’s configured. Without that, we are just guessing.

Can you screen grab your firewall filter page and attach it here???