Strange behaviour when hiding a trace in a plot with many filling traces #2380

If you have around 10 traces or more in a plot that fill to a neighbour, clicking the legend to hide an individual trace can lead to strange behaviour from filled areas.

It appears that, generally, clicking the legend entry for a trace (the uppermost non-filling trace in the CodePen example below) that does not fill to a neighbour and whose hiding makes the plot rescale, will make a filled area get an incorrect shape. If you zoom in or out, the filled area gets its correct shape back. If you manually adjust the zoom level before you click, the issue does not seem to occur.

Another issue, possibly unrelated: if you click filling trace 7 or 2 in the CodePen example below, the filled area that should have expanded instead becomes empty. Manually setting the zoom level does not prevent this issue from occurring. However, here as well, the plot is corrected upon zooming; and a similar amount of traces seems necessary to trigger the bug.

CodePen