Extruder/nozzle keeps clogging up
I can see from the photo that filament melted and frozen thicker inside extruder. This is the problem and not the clogged extruder. This thick part produce a lot of friction and actually diameter grow until the print finally will stuck. Basically I had the same problem and I could guess that you are also using Bowden setup. The length of this built thicker part is actually corresponded to your retraction length setting in your slicer (the default value in Cura is unreasonably big like 6.5 millimetres). I solved the same problem by decreasing retraction settings to about 2-3&nbsp;mm. Just try it and I am sure you will not have this problem again.