Yesterday while readjusting the tension on my machine. I discovered this issue, I re-glued the little black felt thing and it didn't fix the birdnest underneath. So I took the bobbin case out of my Brother PE-770 placed it into the SQ-9000 and my stitches are fine and no birds nest.
I got on Amazon and found a replacement for $7.99.
https://www.amazon.com/dp/B078M2YCDC...roduct_details