Issue plesk panel, domains and SSH ramdomly unreachable

[mrsavvy]

From yesterday all following service are ramdomly unreachable (for timeout of the request):
- plesk panel (port 8443)
- ssh service
- all domains
(The Ping command works. )

But FTP works, and if I access via FTP (in one of domain on the server ) the above-mentioned services returning reachable!!!
I'm reading a lot of forum and checked all logs and repairs tool, but I don't find any error problem or issue in logs errors of server.
Someone can help me? regards

plesk version: Plesk Obsidian Web Pro Edition - Version 18.0.45 Update #2

 

[Maarten]

Have you checked the fail2ban logs / mod_security logs?

Is the server's IP address on the fail2ban whitelist (Trusted IP Addresses)?

 

[mrsavvy]

Have you checked the fail2ban logs / mod_security logs?

Is the server's IP address on the fail2ban whitelist (Trusted IP Addresses)?

Thank you for you reply.

Yes, I checked fail2ban log, no issue. the IP server is in the whitelist. I also stopped the fail2ban server yesterday. But the problem is still there.
It seems that there is a software in the middle that block the requests, but why it unlock all with an ftp request!

 

[mrsavvy]

I added a new domain and the problem is gone, I don't know if it's a coincidence or some configuration has been updated.