The too high light is perpetually on?
If the magnet holders are misaligned or the float or controller is near a magnet, this can be a cause.
I also occasionally see a float that is broken or installed wrong. The post should point up (C Clip on top) and the float will have a black ring inside that should be nearest the c clip and on broken.
This black ring is a magnet that flips a switch in the post, this in turn flips a relay on the controller so the relay and float can be affected by magnets and it is critical no other magnets are near by and the holder magnet is assembled so the bottom of both magnets line up, the outside magnet is smaller diameter to account for trim on in tank installs. Also the float must be installed in the larger C clip, the small one is for the optic sensor, this is a special shielded position. If the float has a broken magnetic ring, it is replaceable and if it is upside down on the post, you can remove the C clip and flip it over.