Glad that you found a way to make things work for you!
Aside from telling us the problems you had, you didn't mention what else you have tried to solve your problem. Just some ideas here, in case you haven't thought of these ......... When you switched from King Tut to the Mettler thread, did you switch the needle? King Tut is a coarser thread, thus needs a needle with a larger eye. Plus when doing FMQing you need a different type of needle than when doing regular stitching, such as when you are piecing. Also, tension may need to be adjusted.
Good Luck!!
May your good day of quilting, return for you again, and again and .....
