I have a 8610 all in one from HP. Its on my home network. When my wife connects to the wireless, she can print fine, however, since her avast updated recently, the “Scan to PC” function on the printer touch pad is unable to find her PC unless the avast firewall is disabled. I assume there is a simple fix for this issue, as her technical tolerance is close to zero, and this extra step makes her crazy. “Why doesn’t it just work like it used too?”
Are you sure it is the firewall and not the behavior shield is causing the problem ?
If it is indeed the firewall, create the correct rule for the scan tool.
https://www.avast.com/en-ca/faq.php?article=AVKB25
It could be firewall mode… puplic or private
https://help.avast.com/en/av_free/12/settings_fw_profiles.html