Seems I broke my Juki-LS-341, again... (Bobbin Shuttle)

[Yoshi888]

Hey everyone,

I love my Juki-341N, but it seems I once again managed to damage my poor machine.

I was sewing as usual, but suddenly it bunched up. I removed my work piece and the thread, but also with the handwheel, it was not properly turning anymore.
So I started disassembling it to see if there was some thread stuck near the bobbin, but there wasn't anything. 
Then I removed the whole shuttle to see if there was anything wrong.

I have attached a video here, and it seems the bushing inside the brass/copper ring gets stuck when I turn the handwheel too fast.
I have cleaned everything I can, and I cannot find anything stuck anywhere.

If I slightly push on the Bushing, it seems to work better, but also after cleaning and reattaching the bobbin, it gets stuck very easily.
I did not want to disassemble it more because I am not too knowledgeable about this, and I am worried about ruining the alignment/timing.

Do you have any idea what could have happened here and how I could fix it?

In case it is relevant, I changed the shuttle a few months ago, but there have not been any problems since then.