ip addresses in blocked site report

I'm seeing a lot of IP addresses under activity for my son, blocked as "uncategorized", for example:

 

67.228.112.201

174.133.30.170

75.125.49.210

69.93.227.202

 

I did a nslookup on a feww, and they turn out to be on the avast.com domain, e.g. a712sl.avast.com.  I believe the access is occuring from the Avast antivirus I installed to replace Kaspersky recently.

 

What can I do to prevent this?