Wrong Sounds

I’m a complete beginner/newby/novice etc. I’m using Cubase LE AI Elements 8.5 (64 bit) on a laptop running Windows 10. I have my Casio Privia electric piano linked via the Midi In/Midi out ports to my laptop via a Roland UM ONE mk2 Midi interface. I also have connected a Zoom R24 for vocals via a mic. I have managed to create some instrument tracks on Cubase - Piano, Bass & Drums, however, every time I click on a track or make a change I get a terrible note / clunk from my piano speakers, not from the monitors hooked up to the R24. Is this normal?
In addition when selecting these instruments and playing them on the piano - the sound coming from the monitors is just the piano sound - not drums or bass etc. But when I play back the sounds are correct, it’s drums or bass etc.
Also, I can normally record vocals via the R24 link up into Cubase, but after introducing the various instruments via the Midi In/Midi out ports to my laptop via a Roland UM ONE mk2 Midi interface, I am now unable to record any vocals through the R24 onto the same recording as the Midi instruments. Could you please advise what I am missing?