Prusa MK3S Print Issues Due to Improper Z-Offset

To confirm an improper Z-offset, initiate the 'First Layer Calibration' print. Observe the filament deposition: if the nozzle is too high, the filament will not adhere or will exhibit gaps; if too low, the nozzle will plow through the layer or cause clogs. Confirm the current value in the LCD menu; a correct first layer will show a smooth, uniform surface where the filament is slightly squished into the bed without rough ridges.

Sources