Tile Images not loading on Mac

First of all, thank you for developing this. It's exactly what I have been looking for and so far, it works great for me. On Windows and Linux. However, on Mac I don't see the map at all, instead I only see grey images. The code I used to test this on mac is /examples/map_view_demo.py from this repository.
I have also tried it with my app, which is running fine on windows and linux. There I discovered that it's only a problem with the display of the map. The marker displays as normal and all behaviour functions properly too. In my case specifically, when I click on the map, I get the coordinates of the location I clicked and the map focuses on that point. By the coordinates I get, I can tell that this is working nicely. The zoom buttons in the top left also display correctly. It's simply that instead of a map, I only see grey. I don't want to post the code here though, because as said, it also happens with /examples/map_view_demo.py from here.
Could it be a bug with the package?
Do I have to install anything else on Mac?
Do I have to code it differently when I want the map to display on Mac?
Thank you for your answer.

Start with /examples/map_view_demo.py and reproduce the grey map tiles on macOS. Trace the map display and tile-rendering path to determine why markers and interactions work while tile images do not; done means the example displays map tiles correctly on Mac without breaking Windows or Linux behavior.