2003 Volvo S60 2 5t Awd Flashed Reduced Engine Performance Subsequently Shut Off

My 2003 s60 2.5t awd flashed reduced engine performance and subsequently shut off and will not start or try to start. Was running fine. Had timing and serpentine belt and 90000 service done recently even changed a coolant sensor and coolant changed. All new motor mounts were installed recently as well and control arms and had volvo dealer address all oil leaks an
d check turbo for leaks and performance less than 5k miles ago. Now it reads low engine compression. Battery checked and is working fine. What could be causing this