Q.Burning Bush
I live in Central Mississippi and have three dwarf burning bushes that were planted in 2008. The burning bushes have thrived and looked great until this spring. All three bushes appear to be alive, and budding can be seen on the branches. However, the buds are not maturing and the bushes only have a few leaves sprouted out at the very top of the bushes. What can I do? All other shrubs in my yard have greened up and are looking great.
Inspect the plant for pests, they could be stunting the plant.
Check soil moisture; they may need some irrigation if the soil is dry.
Check the branches, do they bend or snap and break off?
Do you have any drops in temperature this spring?
Check with your local County Extension Office to see if any other reports of issues have come in with shrubs in your area.
These links have more information.
https://www.gardeningknowhow.com/ornamental/shrubs/burning-bush/burning-bush-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/burning-bush/burning-bush-turning-brown.htm
https://www.gardeningknowhow.com/extension-search/