1. Open the attached project "FlickeringPrefab.zip"
2. Open "SampleScene" Scene
3. From menu bar open ProBuilder Window Tools > ProBuilder > ProBuilder Window
4. Press on New Shape Tool and draw a shape
5. Observe the Scene view

Expected result: Everything works as expected
Actual result: Yellow vertex cursor is flickering and jumping while trying to draw a shape

Reproducible with: 5.0.1, 5.0.3, 5.0.4 (2020.3.36f1), 5.0.3, 5.0.4 (2021.3.5f1), 5.0.4 (2022.1.8f1, 2022.2.0a19, 2023.1.0a2)
Could not test with: 4.5.2 (2020.3.36f1) - There is no menu that would let to create custom shapes by hand

Tested with: macOS (M1. Max) OS version 12.4

Notes:
- There are artifacts in the Editor while creating a shape in versions: 2022.1.8f1, 2022.2.0a19