Q.My neighbor’s Indian Hawthorne bush is not setting blooms though several others are blooming.
There are 3 other bushes in the space and they are all blooming.

Certified GKH Gardening Expert
Here are some possibilities: They need fertilizer in spring and fall. They need full sun to part shade (afternoon shade) to bloom well. Was it pruned in early spring? Indian Hawthorne blooms on old wood and should not be pruned (if at all) till after it blooms. Here are more care tips:
https://www.gardeningknowhow.com/ornamental/shrubs/indian-hawthorn/growing-indian-hawthorn.htm
https://www.gardeningknowhow.com/ornamental/shrubs/indian-hawthorn/indian-hawthorn-pruning.htm