since days I try somehow pictures to the courses, which all have the identical size of 800x600px, suitably from the format under https://lern.de/alle-kurse/ (in the list from top to bottom the first course with a picture Abiturvorbereitung BwR FOS 12th grade Munich 2019 By Lern.De 20 October 2018) on the course description page can also be displayed identically.
I do not understand the size conversions, and I also do not understand why the image is simply cropped at the course description page. Can I control somewhere in the theme or in WP that he keeps with the format 4: 3?
Have tried everything possible. For older courses we have tricked around, that the essentials can be seen in the overview of individual courses, but somehow there must be another way to get existing course pictures in 4: 3 format properly displayed in other resolutions.
I’m currently helpless.