UR24C interface producing feedback when routing an input

Any suggestions what I might be doing wrong, or maybe I’ve missed a permission somewhere. My first interface was a Steinberg years ago, which i used with no issue. I then moved to Focusrite, which I still use for live gigs, with no issue. I purchased a UR24C which I want to use for my home studio, however whenever I try to route an input to the interface it just produces feedback, regardless of any setting. I plug in the focusrite and it works perfectly, change it back to the steinberg, more feedback. I use Cubase 10 Artist, mainly record guitars. I’m sure it’s something simple I’m doing incorrectly.