are you using asio drivers? latency is noticeable if you are using a midi keyboard to enter midi notes - you press the key then there is a lag before the on on the pc sounds

if you use asio drivers, the sound you hear when you sing should be in synch with the vocal as you sing and then when you playback.

if you are using MME drivers you'll never synch vocals and backing track

WAS come close to asio and i've used both. sounds to me as if the backing is playing back delayed but you are being recorded in real time so the error shows up in playback

are the backing tracks midi or realtracks?

even if i can't help, someone else will so tell us more