If the ground speed in the ATC screenshot is correct, that would put them at an estimated IAS of 190kts. If we take the nearby UAE ground speed to indicate they had a ~20kt tailwind while heading to same direction roughly, that further drops their IAS to about 170kts, well within stall range of the A320 at MTOM in clean config.
Does anyone know what the transponder's source is for the reported altitude? This very much is looking like a pitot/static induced problem at this stage. Alpha protection wouldn't let the crew go near the ground speed shown on the ATC screenshot. If it's true...