I have been experiencing the same problem.
I get the same advice from ESET , to block the communication. However I have clicked on the details of the certificate and it says that the certificate has expired.
So, what do you do? How can you report this problem ? Is it ESET ? Is it the certificate? Is it the browser ?
Its annoying because sometimes there is no problem. So can you trust it ? I have been blocking it (most of the time).