Siberblau

I can confirm that Little Snitch is indeed the culprit in this case. The problem, however, won’t magically vanish, simply by uninstalling Little Snitch: Every single trace of Little Snitch must be deleted from your system – including from network settings – as Danila T rightly pointed out. It took me several weeks to get to this point, but Kaspersky Technical Support personnel are to be lauded for their persistence in solving this issue. #Respect. #Уважение.

Thank you, Flood, for your kind reply. I am, indeed, in regular contact with Kaspersky Technical Support regarding this matter, and have already sent them a number of logs, as well as terminal outputs from my machine. Hopefully, Technical Support will find a resolution to this matter which, I would predict, affects a great many people who are running Mac OS 11.1 - especially if KIS Version 21.0.464 is engineered to prevent certain Apple Apps from bypassing firewalls or VPNs - as Eugene Kaspersky himself acknowledged via Twitter in November, ads the screenshot illustrates:

pple Music App (incl. Apple iTunes) blocked by Kaspersky Internet Security for Mac, version 21.0.0.464a.b. Affected machine is a 2019 15" MacBook Pro, running MacOS 11.0.1 Big Sur. I cannot access Apple Music/iTunes App, if Kaspersky Internet Security for Mac is running. My Internet connection is fine otherwise, and I can access other sites or Apps without any problem. Only by turning off Kaspersky Internet Security for Mac, am I able to connect to the Apple iTunes Store. If I enable Kaspersky Internet Security for Mac, the iTunes App Store is no longer accessible: iTunes generates error code -9810. iTunes Error Code -9810 when KIS for Mac is running. Apple Support recommends uninstalling Kaspersky Internet Security for Mac for Apple Music/iTunes App to function. Quitting Kaspersky Internet Security for Mac confirms this compatibility issue with Apple Music/iTunes App. I note that last year, the Mac App Store was blocked also by Kaspersky Internet Security 19.0.0.294b.c.d, on macs running MacOS 10.13.6 (Catalina) Is there a fix, or update, so I can run Kaspersky Internet Security for Mac, AND access the Apple Music/iTunes store? Your advice regarding this matter is appreciated in advance.