Koda1021

I'm hoping to get some feedback and help, because I'm ready to pull my hair out. I purchased a new Juki HZL-NX7 (Kirei). I love the machine and features, but am encountering a really strange issue that I can't resolve.

My main sewing is quilting (cotton). The machine is constantly snagging and birds-nesting. I've narrowed it down to if I'm doing single thickness, all goes smoothly for the most part. But if the machine "perceives" a shift in thickness it suddenly makes a horrific knocking noise in the bobbin area, and the thread snags. When you pull it out, the back of the fabric is loops of snagged thread.

I've tried everything - replacing the thread, replacing the bobbin thread, thread tension, pressure foot pressure, different needle. Nothing works. On a straight path with a piece of fabric that is one width, it's fine. The minute there is any "change", the machine goes bonkers. Just as an example, I'm doing a cathedral window quilt. I'm stitching the points of each envelope. It starts out ok, then gets to the end of the point and the minute it gets to that little bit of bulk from the point, it grinds and bird-nests.

The machine is brand new (just a few days old). I don't have a dealer nearby, and unfortunately can't drive due to epilepsy. The company I purchased from has an excellent return policy. But I do like the features of the machine, so I'd really rather not return it if I don't have to. I'm hoping somebody can offer some suggestions, as it very well could be "operator error" (I'm not ruling that out, this machine is very new to me). I just find it strange that a machine of this cost wouldn't be able to sew smoothly over various thickness material (within reason) without doing this.

Thanks in advance for any suggestions!!