So this is a strange development ive been having lately while sewing fleece. When i try to use the zig zag stetch stitch, things look like all is well on the top side while you are working, but on the underside, there is this problem going on in the photo. The underside bobbin thread seems to be stitching in loosely in some places, while in other places its going in like normal. At first i wanted to see if it was maybe a bobbin tension issue, but the manufacturers have the bobbin tension screw embedded in some kind of yellow stuff that prevents it from being adjusted at all (its a top loader by the way), it only does this with the zig zag stretch stitch, the straight stitch works just fine. It doesnt seem to be affecting stitch strength, but still thats rather ugly
