Preview not working proberly showing old incomplete content

Hi team,
I just had opened one time a ticket about this. The “problem” we found last time was not the real issue.
Symptoms:
In the beginning of working on a site the prview works. As more will be changed as worse it works.
At the example we get showm part’s of the preview.
When I move the complete first section down. In the preview it will be shown still incomplete at first position.
I updated the theme yestereday evening and WP is also up to date.
I deactivitated the caching end deleted the webseite cache. ALso the Browser cache.
I lookt at other threads about this topic that ended with the hint to open a new one.

The client is just thinking to change the theme. But normally the support from your team is excellent and the theme is in place at thousand of websites. So I guess there is a solution or a reason of some elements as root cause.

In the page example also the section in the moddle is not shown over the complete wide in live view. In preview it is full width.

Rhanks fro your support in advance.
Greetings
Michael