in the Customizer under general settings I activated all the options – combine css, dynamic css and smooth scroll. I’m pretty sure there was a fourth option above the icon type box which I also activated. When I deactivated all the options again (all at once), an error message occured and now I only have the three options mentioned above left.
However, I’m not sure if this has something to do with my problem:
In Elementor page builder my submenu indicator is displayed correctly. It is not displayed on the live version of the website, though (see image below).