corporate KES11.1 (and KSC10) and Internet connection

[ak01]

I noticed that KES11 tries to connect sometimes to ds.kaspersky.com even when KSC is used as KSN proxy and the updates get downloaded from KSC (I checked the reports, it always uses Kaspersky Security Center as update source). Why is KES connecting to that specific URL? We have some PCs where users are logged in which do not have internet allowed (get a proxy authentication) and of course that triggers KES to bring up a proxy authentication message (for this URL). I have KSC 10.5.1781 and KES11.1.0.15919