Thank you for your reply, and my apologies for the delay in mine!
Although the problem was lasting for a couple of days already, it seems like everything resolved itself. This morning EIS updated automatically to the latest version and everything is back fully protected.
I read there were some other users experiencing similar issues, so perhaps it took a couple of days before the fix patch reached my computer? Would you like me to run the diagnostics report anyway? Maybe it contains useful information for you to find the cause of these problems? It's the same for me, since the issue seems resolved now.