Resolved code crossed out

Why is it that if i choose a preset like for the template that it does not work?

Clear Joomla cache.

And for example, why is some code crossed out?

Crossed-code means that for these properties using a different code with a higher priority. Look further and you will find it.

Or, the code uses vendor prefixes that are designed for another browser, but they do not work in your current browser. (this is necessary for cross-browser compatibility)

I can confirm that if i clear cache, nothing happens...

And how can i see the higher priority in the code?

I can confirm that if i clear cache, nothing happens...

In this case, wait for a response from the Joomshaper stuff that would give them access to the admin panel.

And how can i see the higher priority in the code?

You should have an understanding of the code and you should be able to use code inspector - the only way.