The Byzantine Era influence on medieval art is more easily recognizable due to it’s hyper-focus on religion. I feel that the medieval art still does not have a lot of the style and technique from the classical era and the content is largely different. When looking for influences from the classical era on medieval art the most prominent and distinguished examples I could find were the images of angels in the Book of Kellis.
I feel that it makes sense that Byzantine art would have the greater influence on Medieval art as they are closer time periods. My parents generation has a greater influence on my generation than say my great grandfathers generation. The Byzantine era split from Classical era styles and that shift carried over to the Medieval Era as part of art evolution.