Turbo Speed Sensor Code #687

[Stoneman]

Thank you for letting me join the forum i appreciate it. Im looking for advice and input on what could continually trigger the turbo speed code. the engine is bone stock 565/1850 X15, Date of MFG. 8/20. 496,000 miles. Had it to the dealorship and they changed Turbo Speed Sensor, Turbo and Actuator, Egr valve, intake pressure sensor, charge air cooler. Im going broke with the shop just throwing parts at it, any good advice?