Thanks so much for looking and commenting I'd like to save these shrubs before fall.

Too much or too little water?

I think you have an issue with how well (or poorly) your shrubs are rooting out into the soil volume surrounding the original soil-less media of the container. The roots were likely incredibly pot-bound, and unless you went to extreme measures to change this condition, then the shrub is mainly taking up moisture and nutrients only from that original container soil volume. That's a problem, and this condition can express itself as chlorotic (yellowish) foliage and meager new stem growth primarily because the plants are having difficulty absorbing enough moisture and nutrients from this limited soil volume. New roots need to colonize wider soil volumes so that more moisture and nutrients can be exploited.

You can apply granular and/or liquid fertilizer to attempt to increase these plants' nutrient levels. You can probably "green them up" pretty easily, in the short term. Long term, I'd consider lifting the plants during the dormant season, loosen the root systems, and replant into a well-tilled garden bed. These viburnums will thank you.

You may well have some insect pests present (scale, etc.) but those are most likely secondary pathogens. Take a sample of your plant (24-36" section of branch) to your local Cooperative Extension Service office for diagnostics.

Post-script question: where do you garden? I am in central KY, zone 5b/6a. Viburnum carlesii are not great performers here in summer heat/humidity; they do much better in zone 5 and north. Viburnum x juddii and some of the other hybrid clones with V. carlesii as one parent do much better, with genetics bred into them from more southerly species of viburnum. Hot summers can lead to more foliar problems and increased insect pest activities, too, due to stressed plants.