Maybe ABS sensor related, but you need a scanner to be sure...
1. They had to remove some stuff and reinstall all correctly but the computer is now confused
2. Forgot to re-attach ABS sensor
3. ABS sensor / wiring damaged or sensor dirty covered in something
4. Brake line / component damage, unbalanced brake fluid pressure between lines (but most cars use handbrake light to indicate this problem, not sure)
5. Did they bleed the brake system? Maybe air pocket in ABS motor
Traction/stability control require the computer to use 1 or more brakes at individual wheels to balance and set the direction of car during crazy situation
Stability system faulty = ABS still can function
ABS system faulty = almost all stability system cannot function