My machine has an auto foot lift. When I FMQ I have to turn it off.
Maybe your machine has one????

No, I have a Bernina with a hands free knee lifter that will lift the foot when I want it to, and I use it in FMQ and it will release the tension so I can move easily from one place to another(no stitching going on then). But you have to put the foot back down or you have no tension.

Haven't tried free motion quilting, but been reading up on it and hope to try it soon.

Always try the most simple thing first. Did you drop your presser foot?

sounds to me like its not correct foot for machine, I dont think its u.

On youtube Leah Day took the spring off of her free motion foot. I have watched her and she makes it look so easy but as of this time I still can't get it right.