Hi, I'm having a strange problem that appears to have started since I had a jam. When I start a print the first layer doesn't happen due to the nozzle being in contact with the bed. I have gone through the calibration process for the z axis and it is still doing it. At the end of the calibration process if I manually move the z axis up to the 0.00 position it is correctly just above the bed but as soon as I start a print it reverts back to being touching. When the print starts it shows the height of the z as 0.09 on the info screen but if I go into the move axis menu option it shows the z position as 0 and it is physically pushing the whole carriage up. If I carry out an auto home it correctly goes back to the correct z height again with the 0.00 being just above the bed. Any help is appreciated.