Extruder Slow Feed Rate on second layer  

Extruder Slow Feed Rate on second layer

Hi everyone, 

We got our Original Prusa MINI+ in March 2021 and it has been working fine until November 2021 and now all of a sudden it is refusing to print and it feels like we tried everything. 

We first noticed the error when all the prints started looking a little strange and then we heard a ticking sound, so my husband cleared the extruder, tightened the spring. He also replaced three parts: the nozzle, hot-end and heat brake tube just in case and there is no problem with PTFE tube.

However, the printer is still struggling to print. The first layer prints fine and then he need to manually apply pressure and push filament to help the extruder prints because the pulling rate slows down massively. He tried to increase the temperature and the extruder still struggled to pull the filament through. He also manually increased flow rate, but same thing happened. He made sure the teeth are clear of debris in the extruder and still no change. 

We can't stand by the printer for three hours for the job to be complete. It is really frustrating not knowing what is happening and not be able to work 🙁

Any ideas on what could be happening? Is that it for the machine? Do we need to replace other parts? 

Many thanks,