USB-C is a collection of standards rather than one standard. As others have pointed out, two USB-C devices can use the same standard yet not operate together.
The standard covers both 20V and 5V power supply. If the device needs 20V and only gets 5V, there is nothing that says it must work, or even inform the user that it, in fact, is not working.
The standard covers both 20V and 5V power supply. If the device needs 20V and only gets 5V, there is nothing that says it must work, or even inform the user that it, in fact, is not working.