I have a basic particle system with a cube emitter, uv sphere particles, and a plane as the ground with "collision" on. when running the sim, particles sit half way in the floor. If "size deflect" is active the particles stop far above the ground plane.
please help
Edit: picture is particles "at rest on" the ground plane
blender versions 2.90 + 2.90.1 macOS 10.15.4