Build manual says "move IR sensor as low as possible". So it' s a centimetre or two below the nozzle. Later you do the first Auto Home with Z offset set to "-5mm". So the nozzle is then a LONG WAY above the glass plate. Then you are supposed to move the glass bed up until it touches the nozzle, in 0.1mm increments. I can move it up 5mm. But no more. So the bed is still a long way from the Nozzle? What to do?