I have a new 5 Pro that has decided to grossly underextrude. Prints now come out as strings woven together. Have replaced nozzle, cleared tube and I can freely push filament thru a hot nozzle. Extruder calibration pushes 47mm of filament instead of 100mm. Filament is 1.75 white PLA. Have adjusted tension spring on extruder with no change. Any ideas?