After installing the Presonus Universal Controller software v45526, and then reboot, I can play YouTube videos back and the audio output is fine, but if I plug in anything into line input 3/4 (for example line out from my PreSonus 192 on another computer).

I can't hear anything and no output meter activity. However, I know there is input because if I adjust the line input high enough I'll get the clip signal.

Firmware has been updated to the latest ... v1.49. What seems strange is that when I click on AudioBox image in UC app, nothing happens. On my other PC that runs the Presonus 192, in UC, when I click on the image I get the mixer displayed. Am I missing something for my AudioBox 1818?

I'm hoping I've missed something very basic or maybe don't have all the software installed?

I am running Windows 10 1709 build. I've also opened a support ticket, but was hoping to get possible solution sooner?

Cheers, Rob.