No you don’t constantly have to uninstall read all of this topic and you will see it isn’t normal, but a problem with the new licensing function. In over 13 years of using avast I have never had to uninstall and reinstall avast free to register again, this is a recent issue.

You shouldn’t have two resident (on-access) AVs installed at the same time, there is a strong chance that they will conflict. If you want Avast free on your other system then you would have to uninstall the current AV first.