Hi,
Can you please try the latest version of Avast (22.10.6038)?
I've installed it, but I will need to report back later to see if the issue occurs again. As I mentioned in my original post Avast doesn't always affect the network like that. Sometimes my internet is fine, sometimes it doesn't.
I do need to mention also that Avast seems to be affecting my computer's sleep/wake cycle. When Avast is turned on, it makes my computer take forever to enter sleep and wake up. It's to the point that I thought my computer is broken.
The issue disappeared when I temporarily uninstalled Avast. I'm now putting up with the slowness because I need the shields, but yeah... (My laptop is windows 8.1 so I imagine it might be an OS compatibility issue?)