I had the Samsung leather case and there most definitely is a problem with Type C cables not fitting through the case. The problem does not exist with the Samsung cable that comes with the phone, but --DOES-- exist with other cables I have AND with the Samsung cable that came with my Galaxy S8.
I returned the Samsung case and am now using the Incipio Duo case. This case accommodates my Type C cables (barely), but has four odd ridges on the corners that are sharp and uncomfortable. I have now ordered the Mous Limitless 3.0, which should arrive next week.