Sounds like bushings and they have techs lacking experience. The bushing will also quiet when it gets colder and start making noise again when it gets warmer or heat from the engine bay warms them causing the parts to expand.
I had a vehicle the was silent in the winter but in the summer at 70F+ started creaking. 100F+ sounded like the Titanic, would turn heads in parking lots going over speed bumps.
Tell them to try soaking down the sway bar and control arm bushing with silicone spray and use the spray straw to try to force it in the center of them.