No live monitor return from Cubase in my UR22 interface

I’m missing something simple and obvious in my setup. I have a Steinberg UR22II interface to my Windows 10 PC running Cubase Elements 12. The interface’s audio output runs to a small stereo mixer. Cubase Studio Setup has the Yamaha Steinberg USB ASIO driver and the Audio Connections have the UR22 as Inputs and Outputs. I have a Modwave synth connected to the audio inputs of the UR22 and I can hear it as a Mix Input on that (in mono) but there is no output coming back from the DAW - if I turn the Mix control on the UR22 to DAW, the synth is silent but other audio from the DAW is present. Once I record a synth audio track into the DAW, I can play it back and hear it.

I want to monitor the synth’s return from the DAW as I play (I know there are latency aspects to consider) but it doesn’t appear. What have I set incorrectly?

If you want to monitor the input signal going through Cubase, you have to activate “input monitoring” with the little speaker button at the bottom of the track in the mixer.
Usually direct monitoring with the audio interface would be preferable, because of no added latency. I’m sure it can be done with the UR22, too, but you may have to consult the manual.