There is no specific error in the browser.
The issue appears sporadically... I have to use the system a lot. Since it's my wife's machine, I don't get to do this often... but I'll try to collect logs and pings in the future (logging is now turned on, as requested...)
Still, to detail a bit more, the problem appears and then I disable all shields, then after about 15 or so seconds, the connectivity is restored. Note, again, this does NOT happen on our other laptop (older machine, Win10). I can then re-enable shields and the connectivity remains fine until the next random time that it fails.
I did check pings once in the past, and those failed as well. Network connection says I'm still connected to the router, but that there is no internet connectivity (according to windows, at least).
Remember, I also ran this machine without Avast for a few weeks (just with Windows Defender) and had NO issues during that time. Only after installing Avast did the problem crop up again.