The shrub you refer to as a Boxwood is actually a Japanese Holly (Ilex crenata, maybe cultivar 'Helleri' though it's hard to tell). These two shrubs do look very similar, but Japanese Holly has slight serrations on the leaves whereas Boxwood leaves are smooth-edged. A more clearly-seen difference between the two is that Japanese Holly foliage alternates along the stem, whereas Boxwood foliage grows opposite each other along the stem. In either case, while each has its own set of potential pests or diseases, we don't see signs of an issue on this plant. Yellowing and shedding of some of the older leaves on evergreen plants is normal in spring, especially during the time new growth is emerging. This shedding should slow and stop by summer. If it were to continue, that could be a sign of over- or under-watering.

The Vinca foliage may similarly be shedding due to acclimation to growing conditions, especially if it was recently planted. We don't see signs of pests or disease and the rest of the foliage looks good. This looks like Vinca major, the less cold-hardy of the two creeping Vinca species that is mainly used as a seasonal/annual accent plant. If instead this has overwintered, the discoloration could be attributed to old growth shedding in the same way the holly is. While that in and of itself is normal, an overarching concern is that successfully overwintering Vinca major can be an environmental risk with regards to invasiveness. Both species and the widely-planted Vinca minor are known to escape cultivation and colonize wild areas to the detriment of native wildflowers. If it is consistently surviving the winter in your area, we'd recommend considering removing and replacing it with alternatives. Otherwise, the plant appears to be healthy and no action needs to be taken.

Miri