Exceptions Setting Not Saved

It appears that Avast is causing me to be disconnected from a Minecraft server. To fix that, I’ve excluded the folder .minecraft in Avast. It seemed to fix the problem until the last few days. Then the disconnect problem resumed. I checked the settings/exceptions and .minecraft no longer showed as an exception. I thought that perhaps there was an Avast update that reverted to defaults, but when I again entered the .minecraft folder as an exception, the problem continued and when I checked settings/exceptions, it was again missing.

First question is why is it not retaining that as an exception and how do I fix it?

Second question is why dose it cause a disconnect at all? Minecraft works fine in the single local game mode, but disconnects from the server in multiplayer mode.

Thanks!
Optiker