getViewport returns incorrect viewport height

getViewport returns the viewport height the same as the scene height when the page is taller than the browser window. The viewport height should be less than the scene height.

Oddly, an SSCCE for Ellie doesn't reproduce the issue: https://ellie-app.com/9LzKBNqhf7Va1 (see console logs)

I've tried on two different computers, same problem. Same in Chrome and Safari. I suggest downloading the Ellie to try it on your machine to reproduce the problem.

[Augustin82]

We've been affected by this as well.

Our workaround was to use a "reference" element in the viewport, that is at position 0, and use its position to compute the actual viewport offset.