Thanks for posting in the Community, SteveMc1.

I can see a reported product investigation about the unexpected behavior you've encountered with unpaid bills, which were not sent daily from your QuickBooks Online account. If the issue persists, I recommend contacting directly our Customer Care Team. That way, they can re-escalate the issue back to the engineers.

As a work around, you can also run the Transaction List by Date report to show unpaid bills and send report daily. Here's how:

1. Click on the Reports and type Transaction List by Date in the search bar.
2. Click on Customise button and select the Report period.
3. In the Rows/Columns check the Name, Transaction type, Due Date, Amount, A/P Paid, and other fields you wanted to show in the report.
4. Click on Filter section and tick box for Transaction type - Bill, A/Paid - Unpaid.
5. Click on Run report.

For more details, check out this link: Customise reports in QuickBooks Online using modern view.

Post again in the Community if you have another QBO concerns.