Upgrade from R77.30 to R80.30

[User-checkpoint]

One of my customer has 2 physical location have each firewall cluster with a centrally managed management server after management server OS upgrade R77.30 to R80.30. Gateways are not communicating to the management server until reset the SIC, We can see logs are from firewalls but gateway objects still not actively showing current status. We did management server OS fresh installation with database migration one location gateway cluster still in R77.30, but other gateway cluster upgraded to R80.30 after SIC reset upgraded cluster gateway successfully communicating to SMS. But R77.30 gateways SIC showing as communicating but I cannot view device status in SMS.

So Is it mandatary to reset SIC after OS upgrade?

[PhoneBoy]

A SIC reset should not be required if you upgrade either the management or the gateway.
What is required after you upgrade one of the components is a policy installation.
That means: after you upgrade the management (and before you upgrade the gateways) as well as after you upgrade the gateways.
This should re-establish the necessary communication.