I can't be sure, because identifying insects from photos is very challenging. I would say that these look a lot like an insect called Boxwood Psyllid (Cacopsylla busi). They are a usually minor pest, but can cause severe leaf distortion or twig death in some cases. They have a very short life cycle and only one generation per year. This means that they are almost done for the year at this point and the boxwoods will have the rest of the season to recover from the damage. They mostly cause distortion of the leaves (cupping), which can be an aesthetic issue, but does not cause significant physiological damage to the plant. It can be challenging to reach them with insecticide sprays, since they are protected within the cupped leaves. You can clip the affected shoot tips now, while the psyllid is still in the nymph stage and destroy them. This will reduce your infection next year by reducing the number of surviving adults. You can find more information and management option in this article from MSU Extension: https://www.canr.msu.edu/news/boxwood_insect_pests