Sitecom USB-hub with keystep (not working)

Hi,

I just got myself a little sitecom powered usb-c hub hoping it would let the op-z talk to the keystep.

It’s powering both nicely, but it doesn’t seem to let them talk to each other.
I enabled midi in and out on the op-z and tried with both midi and usb mode on the keystep.

Is there perhaps something I’m missing, or is this hub simply not gonna work?

Best regards!

Edit: it only works through the hub if I don’t power the hub. E.g.: it only works if the op-z is powering the keystep. But then I might as well plug it in directly ; ;