Waterfall is showing strange see-thru bits

[drscotthawley]

As you rotate the waterfall plot, for certain angles, parts of surface you're viewing will disappear and you'll see thru it. Makes it hard to view the plot.
This didn't happen in previous versions; i.e this is new to the Python 3 / QT5 version. May be related to the qt5agg backend. Not sure if this is fixable on SHAART's end, as it just calls matplotlib for this feature.
Seen on MacOS.