Filament stuck in E3D  

Filament stuck in E3D

Hey,

I have my MK2 since about a year and I never had any issues with printing awesome stuff.
But since three days [perfectly timed with Christmas :'( ] I have the exact problem described here : https://shop.prusa3d.com/forum/others-archive--f66/clicking-printhead-filament-stuck--t14916.html#p71522

I did as they recommended and printed a collet clip for myself ( https://www.thingiverse.com/thing:2585970 I modified it a bit cause it didn't fit into the gaps properly).

I also made sure that the tube was pushed back as described in this picture:

Still.. after 20-30 minutes my filament gets stuck. I have to remove the filament and cut the last few centimeters from it and load it again. after that it works another ~20 Minutes. Its not breaking or getting stuck before the PTFE tube!

Since the mentioned fix didn't work for me. Has anyone the same issue and some ideas for me?
Its also unclear to me why that is happening now.. I haven't upgraded the software nor changed/relocated the hardware.

I desperately hope for help!

Thanks in advantage,
Lukas

// edit: apparently I have the latest firmware on my MK2