When I remove powered tiles, a tiny grey bit in the bottom left corner remains along with the wire. Also after I place a powered floor tile, I can't place any thing else on that spot other than different floors, even if I remove the tile.

I've tried restarting the world but didn't fix it. Haven't restarted the game yet though.

Full restart didn't fix it.

I'm not seeing this little gray bit. Also, I'm able to place assemblers, lights, laser turrets, etc. on powered floor tiles ok, and they get powered if the floor tiles are fed.

Do you have other tile related mods installed?