Media Bay Previewer has no audio!

In my Cubase Pro 9.5.3 Media BAY: I can’t hear any audio when I’m previewing drum hits, synth sounds, loops, etc…what could be causing this? I’m browsing content I know for sure I own and have licenses for…and also when I drag and drop a loop into my cubase project: then I can hear it fine…But then while browsing/auditioning content in Media Bay: I hear no audio! I see the waveforms, and see the cursor/playhead move across the loop when I hit the play button in the previewer winder, but still I hear no audio! My UR22 is working fine and I have audio via the cubase project–just not when using Media Bay Previewer! It’s driving me nuts! Any idea what I’m doing wrong?? (I’m on iMac running Mac OS High Sierra 10.13.5)
As always any expert help and advice greatly appreciated

no audio when I click the play button in the Media Bay’s Previewer window

Set up your control room correctly (if used). There are plenty of posts on the forums, covering this. Use the search.