Steps to reproduce:

1. Create a new project, or open an existing one
2. Make sure that the ProBuilder toolbar is open
3. Make sure that Grid Snapping is enabled
4. Enter the isometric top view
5. Click on the New Poly Shape button in the ProBuilder toolbar
6. Start clicking around in the viewport
7. Notice that Poly Shape vertices are not snapping to the grid

Notes:

- This was working fine when Pro Grids was still around. Now that the Pro Grids functionality had been integrated as a native feature, snapping no longer works. This might be perceived as a regression by some users