Q: Screen shaking on Netflix

Hi all,

I have a macbook pro, retina screen, running OX Sierra 10.12. Just noticed tonight for the first time that when watching Netflix in safari (or google chrome) on full screen, the screen sometimes shakes as if glitching on a scene or lagging. It doesn't happen continuously but I feel quite concerned as I have have never had this issue before and I have had my MacBook for about a year. I'm a fairly new Mac owner so I have made an appointment at my local Genius bar to see if there is something strange perhaps downloaded in my computer by accident (malware? While streaming a tv show I noticed some strange websites automatically download a file which I always immediately drag from downloads to trash, then empty trash) or if I am causing the issue, but in the meantime, I thought I would ask here if anyone has had the same issue? Any suggestions?

Appreciate the help. Feeling worried.