VSR: How to avoid router to route over floating fill

Hi,

I am trying to resolve an issue where router is routing a metal layer directly on top of a floating fill layer of the same layer. Are there any constraints to set to avoid this. This is causing a short and thus failing LVS.

example:

m2 fill layer exists in the layout and not from the router. After VSR run finishes, ports are being connect and in the process the m2 drawing from the router draws directly on top of the m2 fill. How do we prevent this?

thanks!