USB-C is a really bad connector for laptops to displays specifically. I feel like the port or the cable start to break way too soon because there’s nothing securing the cable. Bring back VGA screw in thingies. Thank you for your attention to this matter. 
This is down to the USB PD standard which requires some degree of communication between device and charger to negotiate the charge rate so dumb devices that just want the 5V 1A from standard USB won’t charge as they can’t communicate.
Being still USB, the default is still 5V @ 1A even if the device won’t communicate or doesn’t support PD.