Wiat, I recently obtained a thermal camera with USB C that charges only woth USB A -> USB C cable, but not with any C->C cable. Am I understanding correctly that adding a pullup resistor to the camera could solve it?
The USB-C spec added cc1 and cc2 which allow a device to tell the host what voltage to provide. Since not all devices need special voltages and an extra IC cost money there is the option to tie both cc1 and cc2 to a 5.1K pulldown resistor each. This tells the host to deliver 5V at max 3A.
The maker of your device like many just switched the connector from microUSB to USB-C not reading the spec.
So yes, if you add 2 pulldown 5.1k resistors your device should also charge off a USB-C host. That may however not be worth the effort as to how small USB-C connectors pin footprints can be.