You’re probably judging the sharpening at Fit or other reduced-size zoom. You should only judge sharpening at 1:1 zoom, as the warning exclamation-point indicates in the Detail area if you’re not a 1:1.
Does sharpening in Develop and Library look different when you zoom to 1:1?
Sharpening needs to be judged at 1:1 because the resampling-for-the-screen methods LR uses in Develop and Library are different due to speed being of utmost importance in Develop and speed of resampling is less accurate.
LR sharpening is done in two phases, one in Develop in the Detail panel at 1:1 zoom, where you judge the tradeoff between noise-reduction and sharpening.
The second sharpening is done at Export time after you’ve resized down to what the final size will be. There is no way to judge Export sharpening be using Fit view in Develop.