It could be the fabric seems to be thicker in some spots. Maybe use a thinner needle.

Do a "dental flossing" of the thread path using sewing thread. That may help.

Have you made sure you have the correct bobbin in? I have so many machines and it turned out my "big" problem was I had the wrong bobbin in mine.

If you all will read back, you can see it was the needle---always check that first! New does NOT always mean OK---

Thank you gal lol :D

Are you using the same thread in the bobbin and needle?

Also a 11 needle has a fine eye- some threads do not pass thru smoothly.

Wow. I would say clean every concievable area with a small brush, a kids paint brush and plenty of blowing air into the parts to see if there isn't a tiny piece of something caught somewhere.

I had a major tension problem with that pinwheel quilt entered in Joannes. Wound up adding a layer of muslin between the batting and the backing fabric, changing to Microtex needles and using Sulky clear thread on the bobbin, with YLI on the top. Sometimes you just have to try different combinations. and try, and try, and try.....

Have you tried sewing on a quilt sandwich with a different fabric? Could it just be the combination of fabric & batt that you are using this time? If it persists I say take it to the repair shop. It could be a thread stuck somewhere you can't see it & I know from experience that can ruin your machine if it's digital.

I hear that. I was trying to LAQ yesterday and the threads were breaking like crazy. I pulled out the new needle I had just inserted and it actually had a burr on the tip. Threw that out and put in new needle...better- but not there yet. Then took out the bobbin, turned it around and reinserted it..success at last! That needle was horrible? Do you have your needle in correctly! Mine will only let you put the needle in one way. Do hope you get your's working soon.