I tried blocking it by application filter and then enabled Scan HTTPS, but still it cannot be blocked.
Note: Messenger can be blocked and also "unable to connect to chat" but I'm still able to chat by opening the inbox.
Am I missing something?
Hi Lim,
go to Applications -> Application Filter and Add new Filter Policy or use one that is already there if you want to block more things.
After that you have to apply this Application Filter to Firewall Rule and you've blocked the Chat.
Cheers,
Olli
This is the filter I used, sir
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When I enabled Decrypt & Scan HTTPS, FB will get blocked completely. 
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