Welcome aboard to the Community. I can help you figure out the cause of the timesheet issue in QuickBooks.
Cases like this usually happen if there's a user who made changes to the time entries. For now, I recommend using the audit log to track any activities related to the timesheets.
Please follow these steps:
Click the Gear icon in the upper-right corner.
Select Audit log.
Edit the filters, then hit Apply.
For there, you'll be able to identify any changes to your timesheet. If there's a need to correct the details, you have the option to edit them on your end.
Here's how:
Click the + New option in the upper-left corner.
Select Weekly timesheet.
Choose the name and period.
Make the necessary changes.
Hit Save.
If you're referring to something else, like QuickBooks Time, please let us know. You can add more details by leaving a response below and we'll be sure to get back to you.
For additional reference, I've attached a link you can use about how to manage entries using the Time tab in QuickBooks Online Plus, QuickBooks Online Advanced, and QuickBooks Online Essentials: Track and manage timesheets in QuickBooks Online.
Feel free to hit that Reply button if you have additional questions about your timesheet. Have a great day ahead.