Abnormal issue..Checkpoint

Ok, here's the setup:

User vlan------>Checkpoint------->Server Vlan

User vlan------ 10.10.1.0/24 Server Vlan------ 192.168.3.0/24

The problem is intermitent...

From time to time user 10.10.1.4 ping to server 192.168.3.3 goes to 200-300 ms in the same time ping from the same user to the internet 8.8.8.8 is <1 ms.. The same time when ping goes high for user 10.10.1.4,,, ping from user 10.10.1.110 to 192.168.3.3 is normal...

I checked switch ports, i checked If Checkpoint is doing some kind of traffic scaning, i disabled antivirus in station PC...

In my vision If there was a physical problem, like a switch-port or cable, traffic would have droped to the internet as well, not only to the server 192.168.3.3 or If there was a problem with the server conection the problem would manifest for all the user's not only 10.10.1.4..

Do You guys, have any ideea as what to troubleshoot next.?

Tnx in advance...