A sewing machine tech said years ago the best needle for FMQ is a Stretch needle, has the best scarf, I have been using them for years & agree.
Since the thread is breaking have you checked the spool, is there a burr or something that could be catching the thread as it passes over the spool.
Another cause is maybe a small piece of thread is caught somewhere in the threading path or bobbin area, that has been the case for me with breaking thread. Often it is hard to find, use a flashlight.
Don't give up!!