Just when you think USB-C cables can't get more confusing...
The USB-C cable that comes with the new MacBook Pro, to connect it to its charger, doesn't not function as a USB-C - USB-C 3.x data cable. It does however function as a USB 2 data cable

It of course
looks like every other USB-C to USB-C cable. I suggest working out a labelling scheme and attaching a very clear label to every single 'USB-C and Thunderbolt 3' cable right out of the package.
Label the ports on the laptop too

Decoding the tiny USB/DisplayPort/Thunderbolt/Power Delivery logos, if they are even present/correct, is error prone.
USB.org provides this helpful list of
USB-C cables
I used Google Translate from the original German,
this article describes how to tell the various USB-C ports apart.
From Intel.
Note the tiny 3 near the squiggly Thunderbolt marking.