See attached images. Some fragments are not drawn.
In image with Bubble chart - on the left upper chart.
In image with scrollBars - on the second scrollBar

I saw such bug on linux and windows.
Reason is unknown.
Usually it looks so: blinking, when scene has just appeared and then some stable state: either some fragment is drawn or this fragment disappear and a gray rectangle is on fragments position.

Usually fragment is the same from run to run.