Thanks for your reply.
SaeMode does not help. However, I found out that exactly the same page on a different hosting provider, also with PHP8, this error does not occur at all. (PHP settings to display errors is on on both) I also deactivated all plugins but elementor, and the error stays the same.
This is the page where the error is displayed: https://staging.spori-holzbau.ch/about/
For PHP info its this link: https://staging.spori-holzbau.ch/phpinfo.php
