Jp,
I have had that happen too. What did I do to correct it ......... , can't remember specifically.
I did disassemble and clean the top tension then adjust it. Same with the bobbin and everything there. I checked the needle plate for burrs.
All I can remember doing is starting at the top and working down, cleaning and adjusting as I went.
It's obvious something is binding the the thread then as you've seen releasing it. You just have to find the piece.
Sorry I wasn't much help.
Joe