Blight on miniature boxwood
This doesn't look good.
How old are the plants and where did they come from?
We are concerned that it is possible that you have a relatively new disease called Boxwood Blight for which there is no cure.
The only way to know for sure is to have samples sent to a lab for testing.
Do you have a landscaper?
They could submit samples.
If not, let us know, and we'll work out a way to have them checked out.
Here is our page on Boxwood Blight with more information on what to look for: