HI Andrew, I took a look at your video, I think @Reese will be able to explain it better than I can but basically the waveform is no longer stored in full inside the DB due to it bloating the DB file size, so it now renders live as the track plays which causes this slight visual issue.
There was a lengthy discussion on another thread (that I cant find) whereby it was calculated how many times it would happen per track and the likelihood of seeing it at the time it happens… it was also concluded its nothing more than a cosmetic glitch that doesnt impact the music or the alignment of the grids as it corrects itself as it flickers.
Edit: try here