The satin stitch is an elegant way to finish the edges of appliqués. It adds a nice finish and ensures that appliqués stay put on the background fabric.
There is a setting on the screen (depending on the setting/stitch you are using_) that is on the far left side and if you press it, it changes colour on the screen to show it is activated and then, every time you stop stitching, the foot automatically goes up and then goes down when you restart. Check the machine manual and you will find this information on page 36 under "Foot up key".
I'm not sure if you mean when you are making a satin stitch or a different type of stitching. Be sure to use stabilizer underneath your fabric when doing this dense satin stitch - that might be your problem?