"Blurred background" mask causes editor to flash image all over the place

Klwp v3.43

Steps to recreate:

1. Use an image as background

2. Add a shape in root

3. Add the "Blurred background" mask to said shape

4. Increase blur value to anything above 0

Result: https://gfycat.com/vibrantpopularlangur

The issue is only present in editor, doesn't affect the home screen, but is extremely annoying when you want to work on your preset.