Created attachment 129755 [details]
Screenshot of the glitches

SUMMARY
The rendering of the vector shapes on the canvas breaks if you drag a shape from the vector libraries.

STEPS TO REPRODUCE
1. Add a few vector shapes on the canvas.
2. Drag a shape out of vector libraries (on the same layer).

OBSERVED RESULT
Glitches on the canvas of the vector shapes.

EXPECTED RESULT
Everything looks correct.

ADDITIONAL INFORMATION
Those are standard vector shapes glitches: no way to get rid of them by changing the visibility of the layer, but it helps if you drag a vector shape from the layer over the glitches (so dragging a shape from Vector Libraries causes glitches, dragging a shape from the canvas fixes them). 

The attached screenshot shows the glitches. The Push Button shape is dragged from the Vector Libraries over the other shapes and leaves a trace of dark grey rectangles (the dark grey is a vector rectangle on another layer. If it was on the same layer, the glitches would *probably* show the content of the layers below).

SOFTWARE/OS VERSIONS
Krita

 Version: 4.3.0
 Languages: en_US, en, en_US, en, en_US, en, pl_PL, pl, pl_PL, pl
 Hidpi: true

Qt

  Version (compiled): 5.12.8
  Version (loaded): 5.12.8

OS Information

  Build ABI: x86_64-little_endian-lp64
  Build CPU: x86_64
  CPU: x86_64
  Kernel Type: linux
  Kernel Version: 5.3.7-050307-generic
  Pretty Productname: Linux Mint 19.3
  Product Type: linuxmint
  Product Version: 19.3
  Desktop: X-Cinnamon