That really is the problem and what my point 2. is all about; how does avast know in the very first installation screen that you are a paid user (not a trial) if you do a clean install (no license would have been input/applied).

I may be that the avast installation setup file may well be able to (check) do this if you either update from the UI or install over the top of an existing version. But I can’t see how it could do it in a clean install.