one of our other cases concerning Boxcryptor and Kaspersky states:
"And if someone else runs into the same problem, I just discovered that
upgrading to their new release, version 18.104.22.1681 solved the problem."
If this doesn't help either, you may try this scenario:
If you really need to access your files in such environments, you can export your keys and use Boxcryptor with a local key file. Further instructions can be found here: https://support.boxcryptor.com/display/DOCEN/08.+Key+export
If you do so the file acts as Boxcryptor server and you don’t need to make any requests to the server.
But keep in mind: In general it’s not recommend to use a key file. Updates, permission management and device unlinking can’t be published to your clients, but if the Kaspersky issue is unsolvable I guess this will be the best practice.