How to reproduce:
1. Open the attached 'New Unity Project.zip' project
2. Open 'SampleScene' and select 'Cube(1)'
3. Make sure that ''Move tool' is selected
4. Enable Vertex snapping functionality by pressing Shift+V
5. Try to select any of cube's vertex

Expected result: Move tool goes on cube's vertexes
Actual result: Move tool glitches between random vertexes

Reproducible: 2019.3.0a3
Not reproducible: 2017.4.28f1, 2018.4.1f1, 2019.1.5f1, 2019.2.0b5, 2019.3.0a5