There are 10/20 and 40 mbs cables - if you use a cable that is too slow, it won't work. Greetings.A

"Commercially available cables" for USB-C are not the right choice; the USB interfaces of the Extreme Portable and the computer must comply with the special SanDisk specifications, i.e. USB 3.2 gen 2 (or 2x2) type C. So look out for Thunderbold 3 or 4 cables, for example!

For USB C connections, I generally recommend using only Thunderbolt cables (with the lightning symbol).
They cost a bit more, but work for all applications.
See also the informative test by Rafael Zeier: https://youtu.be/AkvsNlpq3V...

I have not found a USB-C cable that does not work. However, I no longer have any slow cables (feature: they are usually relatively thin). Cables that allow a theoretical max. data rate of 20GBs are recommended (they are somewhat thicker).

The same behaviour can be observed with many cables, not only with this hard disk. There are cables in different qualities. The same behaviour can be observed when charging mobile phones. Some take an endless time to charge or do not charge at all. Therefore, to be on the safe side, always use the appropriate cable. It's not a problem.