Cubase LE6 not working with Focusrite Scarlett Solo OR with Helix LT

As the title says, I can’t get Cubase to work with any of my interfaces. They both work just fine with GarageBand and with Reaper, but Cubase just won’t budge.

I am running macOS High Sierra 10.13.2 (current to today, Jan. 6 2018). Plenty of RAM and HD space. Both interfaces have their most current firmware installed, and cables work fine, as I mentioned that I can monitor and record just fine in GB and Reaper.

Now to Cubase: it’s the Zoom OEM version. I installed Cubase when I bought my Zoom, but I never used the Zoom as an interface (it was always in my studio, far from home). Last week I tried to switch from GB and Reaper to Cubase…but I can’t. When I use Helix as an interface, there’s no input signal. When I use the Scarlett, I get a nasty white noise and the signal clips at the maximum, no matter what level I set on the interface. The device setup seems correct:

So do the connections:

The instant I enable monitoring, this happens:

I can set the interface gain to 0, it doesn’t change a thing. I tested recording, but the white noise obviously fills anything I record, and you can’t hear any voice or guitar.

I tried everything: mono input, stereo input, mono and stereo outputs, changing channels, etc.

Any thoughts?