Hello ! Thanks for the answer.
The web links component is now working. BUT:
Unfortunately, I could find at least three other errors compared to the original.
Everything in the big desktop view:
1. Module position Top 1A is shown to the left of Top 1B - Normally this position is on top
2. Position sidecol2a has 3 columns in the original (module thumpgallery) and in the version after your intervention only 2 columns (cannot be switched in the module)
3. The module position bottom-1a has a background image in the settings which is not loaded! (I tried bottom 2a as a test, it doesn't work either. Background image is not inserted.)
Here is the original link to the current J3 page
https://www.dks-ev.de/index.php
Here is the link to the J4 test page:
http://dksjoomla4vorbereitung.dynamofanclub-sayda.de/index.php
Here is the link to the module positions test page J4 (strangely enough, it is displayed correctly there):
http://dksjoomla4vorbereitung.dynamofanclub-sayda.de/index.php?tp=1&templateStyle=502