Q.hydrangea not blooming
I read the reasons and fixes for a hydrangea not blooming. I have these hydrangeas very close to each other but one blooms every year and the other in the same soil nearby but for the past 2 years does not bloom. Can’t be the soil and the cutting. What could it be?

Soil can very, even in a short distance.
Avoid fertilizing any lawn areas around the shrub, as the excess nitrogen can migrate into the soil area.
Are the plants the same variety? Is the sunlight conditions different?
This article will help with the proper fertilizing for healthy, blooming Hydrangea.
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/fertilizing-hydrangeas.htm