The estimated start time of all plans and activities under the project has been reset

I am using Windchill ProjectLink Release 11.0 and Datecode with CPS M030-CPS18 The estimated start time of the plan and activity under the project was reset to 8:00 AM on the day the project was created, and the estimated start time of the activity was set three months after the project was created, but it was still reset. The estimated start time and actual start time of the plan and activities under the project are all refreshed to 8:00 a.m. on the day the project is created; There is no error message in the background.