from eading many many posts here about thread it appears to me that NO one thread fits all. Many say machines have a mind of their own and definitely a preference for thread.
You just have to try until you find oe that works best for you I have used serger thread with success. Others have not. Wish I could give you the name of the "magic bullet" but there just aint one. Personally I like the old Coats and Clark but it is hard to find. that is why I boought all that a shop had that was closing. I also got it for .25 a spool.