Distortion in punchin in

hi there, I’m having a bit of trouble when re-taking fluff lines. When I do the so called punch in editing, while I listening back to the track that I am listening to to help me feed into the edit that I want to retake, it plays back a little gritty and rather low pitched. Although I can hear myself fine in my earphones when doing to take. It all sounds Fine afterwards but makes it difficult to get my retake to Blend in correctly. Any ideas?