Well leena, It might not be a bad idea, but I honestly don't think anything's wrong at all.
If there's a slight quality difference to your previous recordings, I reckon it's gona be down to the sound of the room your in, or your distance from the mic, but that mic/preamp combo is certainly working as it should be.
It's only recording on the bottom line because the top line is 'input one' on your interface which has nothing plugged into it.
Your mic is a mono source so the way everything's working is correct. That's how it should be.
Mine's a guinness btw.

Cheers.