Hi, I've been having real weird problems recently with my ultimaker 2+ that has been printing perfectly fine for over 2 years. The brim of the print is fine, but then, when the object begins to print, the filament doesn't stick to the plate and creates a «broken» layer. I cleaned the extruder and the nozzle, recalibrated the build plate, change the filament but nothing seems to work. The filament also shows a weird grinding pattern. What could the problem be?