Can you tell us how it was planted??
ie; In regular garden soil,
or a bagged kind?
If bagged what kind??
Was it fertilized, if yes, what kind
and how, in the morning, afternoon, night?
and was the soil dry???
Viburnums are sorta slow starters in the spring
Give it a wee~bit more time and they should leave out
If not, any chance of a picture??
That helps greatly and we may be able to see/detect
other problems thru the picture!