Waterfall update "jitter" that disappears when spectrum enabled?

We've had two reports of waterfall display "jitter" when new lines are being added to the display. It's important to note that "jitter" in this case does not mean the uneven rate at which new lines are added (people have complained about that for a long time, lol). It means the entire waterfall window actually jumps up and down slightly. This behavior also is reported to stop when spectrum mode is enabled ("Spec" button). The problem may be related to the use of older version browsers.

We have not seen this problem in any of our testing configurations. If anyone else has please let us know details (browser type and version, pc or mobile, Kiwi used etc.)
Thanks!