Colour mixing hotend printing issues

I hope the photo uploads.

I have been having issues with this hotend since i recieved it. It starts a print fine but then its get poor.
Whenever i try to do gradient it has major issues and starts clicking when it needs to start mixing the colours.
I recently found that this is happening and thought it could be causing the "thermal runaway " but not sure why this is happening. The black filament was being fed into the opposite side that it is being shown to leak from on the heater block. This issue could also be the cause for the clicking.

Any ideas of why this could be happening?