In work order When i provide completion date start date is getting removed

Summary:

When i provide completion date start date is getting removed

Content (please ensure you mask any confidential information):

Created Work order based on work definition
Scheduling Method as Default scheduling

Resource and item have been added to the operations

Please suggest what i need to check

Version (include the version you are using, if applicable):

25D

Code Snippet (add any code snippets that support your topic, if applicable):