Cannot connect audio inputs and outputs in Cubase 9 LE

Have you tried another usb cable ? They can go bad.

You could open up the war on another front via Zoom’s support here (they have a community forum):
https://support.zoom.com/hc/en

I’m pretty sure you could update your Cubase to 13 LE. I had 6 LE and they gave me a license for 12. I assume it applies to Cubas 13 too: