@marcan42@twitter.com explained:

I bet it's SuperSpeed/UAS one way and High Speed/USBMS the other.
This happens because you need a mux to handle flipping the SuperSpeed lanes, but not the USB2 ones. Cheapo Chinese designs omit it, which is not compliant with the standard.

@th From memory, there was a great design around recently where someone built a USB-C device that used detection of cable orientation so it wouldn't work until you plugged it and unplugged it once, flipped the cable and plugged it in again, then unplugged it and put it back the first way again.

@th Only provided the automatic orientation configuration circuitry is allowed to do it's job. 😀 That said, I have seen an orientation agnostic Type A connector demostrated so both as possible. It would certainly have made life a lot easier if we had gone that route from the start.

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