what temperature is your preheat set too ?

If you're trying to push plastic through at too low a temp it will click.

For pla - your preheat should be around 215-225c - I have mine set at 220.

When loading different filament don't forget to change the preheat temp to suit the new filament. Pla can be unloaded up to 250c without any issues.

Switching from pla to xt recently the preheat was set at 250. These days I only ever use the load part.
Clip the eisting filament where it enters the extruder and load. when the existing stuff stops coming out load the new one.

Quicker and much easier than trying to unload.

Whatever your printing temp is - try upping it by 10c.
For pla these days, I print at 215 or 220.