Silicone Nylon floors are known for their propensity to leave one bunched up in a corner of the tent after sliding around for a while. However, time and few strips of sealer painted on the floor can do a reasonable job of allowing you to stick to one spot.
Over time, dust and grit will work its way into the coating. This will significantly reduce nighttime slippage.
In the meantime painting strips of sealer on the floor every foot will help to anchor the pad. I’ve know that some people also strip their pads in a similar manner. Since I’ve not tried that method, I can’t comment about its effectiveness.
Good Luck.