Let me clarify things out for your about the status showing up on your HMRC reports.
When the status is Rejected, we submitted the FPS. However, it was rejected by HMRC and it will be under Due Now. You'll encounter this when there's an issue with the Government Gateway credentials. You'll want to check if you've entered the correct user ID and password. See this link: Turn on RTI reporting to HMRC in QuickBooks Online Standard Payroll (UK) to verify your HMRC information.
Another status will show as Overdue when the submission is not successful in the first run. You need to resubmit the file. Here's how: