Q.Half dead burning bush
Last year toward the end of the year, I noticed a few branches of my burning bush just seemed to die all the way down to the base of the shrub. This year about half the bush has died. All on the south side of the plant. I have strawberries planted all around the base and they are thriving. Any ideas on why half the shrub would just suddenly die? I have three other burning bushes in the same general area, but spaced out. One is a bit of a slow grower, but the others are fine.

With the below normal cold winter that nearly the entire United States suffered your plant may have suffered some winter damage.
Inspect the plant carefully to rule out any disease or insect damage.
I would recommend a hard prune and wait and see approach.
Here are some article that will help you.
https://www.gardeningknowhow.com/ornamental/shrubs/burning-bush/pruning-burning-bush.htm
https://www.gardeningknowhow.com/ornamental/shrubs/burning-bush/burning-bush-care.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/winter-damaged-trees-shrubs.htm