When the raster image is set below 100% opacity, it begins flashing or flickering while I drag nodes on a vector shape with the Node Tool.

The issue does not occur in either of these situations:

• The raster image is set to 100% opacity.
• A vector shape is added inside the same layer as the raster image.

In this video, I first demonstrate the flashing while editing the vector path over the reduced-opacity raster image. I then add a vector shape with reduced opacity to the raster image layer, and the flashing stops.

Steps to reproduce

1. Place a raster image in the document.
2. Reduce the opacity of the raster layer.
3. Create a vector shape in a new layer above the image layer.
4. Use the Node Tool to drag nodes on the vector shape.
5. The raster image flashes while the nodes are being moved.

Adding a vector shape to the raster image layer appears to prevent the flashing.

Has anyone else seen this issue, or is there a display or rendering setting that could be causing it?