Random black areas rendered

Version affected: 8 b111.

Various nodes in the scenegraphs are sometimes rendered as black areas.

As this happens within a non-trivial application, I cannot presently offer a simple reproducible case, but I can give some general information about the context within which it appears. I have two seperate stages, in one is a TableView, when a row here is focused the scenegraph in the second stage is updated. After around (consistently) 30 or so updates of the second stage's scenegraph, various unrelated areas in both stages appear as black. On subsequent next updates some different, some same (changing for each update) areas appear black. Minimizing and maximizing the application brings everything black to normal, but then the black arears appear again on the next update of the second stage's scenegraph.

If this is a completely unknown problem I'll spend some time with trying to create a reproducible example.