Do you still see a difference if you view the image at 1:1 in both Develop and Library?
Noise reduction and sharpening must be applied and evaluated at 1:1, where one image pixel is represented by one image pixel. Any other magnification will be inaccurate and misleading because the image has been scaled.
I went to a different unedited image and made my adjustments in 1:1. I was able to replicate the problem: my nicer image in develop but the original one in library.
So, what I did next is: in develop mode, after I made my adjustments, I go to 1:1 looking at a particular part of the photo. Then, I switch to library( still at 1:1). Then, the photo in library is the same as the one in develop mode going from 1:1 to back to fit image. I guess this must be a work around for the problem.