Display update slows right down in multitrack scrolling view

I haven't noticed this before, but if you work in the multitrack view, and you have zoomed in on the display and have "centered auto-scrolling in multitrack editor" enabled, the speed the display refreshes at slows right down.  This is true even if there's only one track used in multitrack view.  You notice it as soon as the display begins to scroll.  All dynamic content is affected, so level meters, phase analysis, spectral display etc. all update much slower.  It looks like they refresh at 5fps rather than 30fps.  I have a Nvidia GTX970 graphics card with up to date drivers installed, so I doubt it's a graphics hardware issue.  Playback and recording of the audio doesn't seem to be affected, just the display update.  I'm on the latest version of Audition CC 2017.1.1.

Has anyone else noticed this behavior?

Regards,

Steve