I would agree. They can slowly sag with time but if this was a sudden change, they weren’t reinstalled with enough preload so you can’t twist them enough with the torsion bolts/keys to get your ride height back.
So the torsion bar is key to the lower control arm. It should be keyed in a way that when the suspension is fully unloaded it still had load on the bar. If this is keyed back into the control arm incorrectly, it wont have this preload anymore.