Hi there!

Thanks for your query.

Sorry for your experience.

This upgrade should not be an issue as per my knowledge. But as you know, Helix ultimate 1 uses bootstrap version 4 and Helix ultimate 2 uses bootstrap version 5, same with fontawesome and many more version upgrading, and yes it's a major upgrade due to Joomla 4 compatibility. Thus many default CSS comes from updated versions of bootstrap, fontawesome and so on. These includes default container width changing for different breakpoits. So, it can be seen different visually after update. Not all the time we are responsible for changes actually:(

For example, if your Header/menu fits well with existing container width value, it can be narrowed down after update, so causes menu droping second line, etc.

It's always better to keep a full site backup regularly and you can update your site. If some minor changes you can see then you may share exact points with us, we will try to adjust then with the new changes so that those mostly look similar.

Hope I was clear enough.

Best Regards