I noticed some nasty rendering artifacts while placing text on my schematic. Dragging the text to the left will leave a trail of letters which is indicative of the area that it thinks it needs to redraw is too small. Zooming in or out causes the entire area to be redrawn and everything look fine.
Similarly, when placing a new part it does render to symbol as you drag the mouse until I middle click on my mouse. Seems to me that it is not attempting to redraw anything in that scenario:
Fusion
