Issues Entering two or more timesheets using the web app.
I do appreciate you for performing the browser troubleshooting step provided by my colleague, davidtps.
I'd suggest contacting our Phone Support Team again so they can open an investigation about the error you're seeing. Just click here and select the Chat now link. I'll also share the article about Timesheet setup: QuickBooks Online and TSheets as future reference.
Always know the Community is available 24/7 to help with any questions you have with QuickBooks. Take care and have a great day!