King Tut can be linty. Try “flossing” between your upper tension discs (with presser foot raised so discs are not tight) using either *unwaxed* dental floss or multiple strands of regular size thread. The tiniest bits of lint caught in either the top tension or bobbin tension can cause skipped stitches. If you have a bobbin case, also check to remove any lint that may be caught in the bobbin case tension spring. Finally, try using a bright light and magnifying glass to look for a tiny piece of lint or thread somewhere in the bobbin area of the machine.