The stepper motor of the extruder might miss steps. Click noise might be heard

The hobbed bolt inside the filament feeder slips over the filament. The hobbed bolt might act as a milling machine and cut the filament, so the filament feeder will be unable to create a force to press out the material, the filament gets stuck.

The filament comes out of the nozzle but has no space below and moves sidewards and sticks on the nozzle (sticky filament as PETG). This is the same effect as when having too little material. This material could then drop back to the bed and cause conflicts as collision with the nozzle.

The part gets some 0.1mm wider than expected