Q.Viburnum Snowball bush
My snowball bush/tree is 30 years old and in spring it always had beautiful big snowballs. This year most snowballs were little and dry/grey and it had some louses. Now the little tree looks very sick, there are no more louses, but many leaves are shrunk and wrinkled. What can I do?

Curled leaves are an indication of a pest issue.
This article will help you.
https://www.gardeningknowhow.com/ornamental/shrubs/viburnum/pests-affecting-viburnums.htm