Thanks for reaching out, and welcome to the community!
I am not aware of widespread issues with the USB-C ports or USB connectivity with the ATEM Minis, but it could be an issue. I would do more troubleshooting before assuming it's an issue with the ATEM Mini itself, though.
First thing I would check is the USB cable that connects the ATEM Mini to the computer. Make sure it is a high quality USB cable and not a Thunderbolt cable. I suggest keeping the cable at 6 feet or shorter, and using cables from brands like Anker, Belkin, and maybe Amazon Basics.
Also make sure the ATEM Mini has proper space around the entire unit for air flow and heat dissipation. If the unit gets too hot it can cause USB connectivity to drop.