Player disconnect causing lag

[cellexpert]

Hi, I have a strange problem in my server.
when a player disconnects cause a lag on the server.

What I've tried to do:

installed the server without plugins
I tried to leave the server default, no addons
try an outdated version of srcds

curiosity ...
if I run the server on another IP and port, the problem disappears
if I run the server on another IP the problem continues
if I change the port the problem disappears

By this I've moved from port 27015 to 27025 that solved the problem for a while
Now it started happening on port 27025
I need to find a solution for this so I do not have to keep constantly changing port.

[cellexpert]

Problem solved!

I was wrong because it was really problem with plugins

The plugin that was causing this problem is the outdated savescores (version 1.1.0)
Just upgrade to version 1.3.4 the problem disappeared

Thanks!