Unusual Network issues on MacOS (relating to Kaspersky)

Hi Experts,

I am experiencing an unusual issues lately, hence I would like to get your opinion.

Anti Virus Application: Kaspersky Endpoint Security (version: 11.0.0.501a.b.c)

Platform: 10.13 High Sierra and 10.14 Mojave

A few months ago after we update the Kaspersky to version 11.0.0.501a.b.c, we got a few MacBooks (about 20% affected) suddenly having no Internet connection. The symptom is extremely unusual as well, below are the symptoms:

1. Safari, Chrome, Firefox will display "Site can't be reached" error
2. Changing WiFi to a different SSID will not work
3. Using hotspot will not work
4. Google search will work, but clicking on any of the result URLs will not work
5. Users using CALL / GET function will not work
6. Ping to any websites will work, either to 8.8.8.8 or www.google.com (definitely not Internet or DNS issue)
7. Using netstat -n -i TCP, it shows Google will be stuck in SYN_SENT

Interestingly, the issue will be resolved if we Force Quit "KAV" in the Activity Monitor, hence which bought me to open a case with Kaspersky to investigate on their end.

I would like to know if anyone experienced this issue before? And if so, was there any permanent fix you found?

Regards,

Sam