Slider Problem after Update / Title is not displayed

We have tried to update our website to the latest wordpress version and the latest template. This has worked well for the most part. However, we have a problem with the slider. The title is no longer displayed in the current version, or only in the Responsive Design and then differently.

The correct version would be:
https://www.artwin.ch/downloads/Temp/artwin_header_correct.jpg

And here is the current display:
https://www.artwin.ch/downloads/Temp/artwin_header_incorrect.jpg

Do you have any tips on what this could be? Were any individual adjustments made in the past? You can also view the website at https://www.artwin.ch (old version) and https://dev.artwin.ch (update version).