sounds similar to a pfaff I had. It would just start stitching like crazy and I could not turn it off except to unplug it. I also had a bernina that made those fantastic bird's nest on the underside seemingly totally randomly while I was stitching. The Pfaff, I brought in a couple of times and as it is random, it never misbehaved for the tech and checked out fine when tested. The Bernina was brought in several times, the tech finally tweaked the timing a bit, but it still happened, that one I traded it in for another bernina that is working just fine. The pfaff tech said that the newer machines have such fine settings that even a spec of lint or static can cause them to behave strangely. I had brought him in a old 1950 ish Singer 66 and he said he loved working on them cuz he did not have to be that precise. If you can bring it in and if you can take photos on your phone of what happened and even, if you can, leave the work in the machine and bring it to the shop. That helps the tech figure stuff out.
Oh, another thing is to check the thread you are using. You need a good quality thread to do embroidery and even then, you can get a bad spool.
Last edited by sewingpup; 01-19-2022 at 06:52 AM.