Q.Dieing Twigs On Nanking Cherry Bushes
I have 3 beautiful nanking cherry bushes. They blossomed vigorously and when I checked for fruit I found that there were a significant number of dead twigs.

Certified GKH Gardening Expert
Nanking cherries are not usually bothered by pests and disease, so at this point, I would just prune out the dead wood. If you see any other worrisome symptoms check these articles for possible problems:
https://extension.wsu.edu/chelan-douglas/agriculture/treefruit/horticulture/cherryverticilliumwilt/
https://www.gardeningknowhow.com/ornamental/shrubs/bush-cherry/nanking-bush-cherry-care.htm
https://www.gardeningknowhow.com/edible/fruits/cherry/cherry-tree-diseases.htm