Broken: Blender 2.8 dc26ef081b9
Short description of error
Once you start changing a mesh in edit mode the 3D cursor becomes confused on where it is supposed to snap to when left clicking.
Sometimes it snaps on the initial position of the polygons or it instead snaps slightly inside or outside of the surface of the mesh or doesn't snap at all. Once you switch into object mode the snapping works like normal again.
This can already be seen by just going into edit mode on the standard cube, moving/rotating/scaling it in any way and trying to left click on any surface of that cube.