Perhaps you accidently moved the switch that enables free hand embroidery? It's up and under next to the pressor foot lever. Slides forward and backward. Forward the pressor foot will go all the way down to the feed dogs. Slid back and it keeps the foot up off the feed dogs but allows the thread tension to work properly. It would be easy to accidently move it when operating the pressor foot raise/lower lever.
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Perhaps you accidently moved the switch that enables free hand embroidery? It's up and under next to the pressor foot lever. Slides forward and backward. Forward the pressor foot will go all the way down to the feed dogs. Slid back and it keeps the foot up off the feed dogs but allows the thread tension to work properly. It would be easy to accidently move it when operating the pressor foot raise/lower lever.