I tried it again but no it's not working. When this code is not in customizer then all courses load like they should (talking about the page with the button on the bottom - buy, start etc).
When I apply the code, the paid courses load fine and the code works, but free courses stop loading (see screenshot).
When I then remove the code again it starts working again, so I guess it can't be anything else.
I've also tried changing the API version, but still the same.
<mark style="white-space: pre;">https://snag.gy/omcZRs.jpg</mark>