This is a program bug and I have been reporting it. I even sent a Video of this to programming staff.
You can report it, too.
Resolution for 'Almost Due Invoices issue: 'I am not seeing any reminders for “Almost Due Invoices” on the reminder page.' available: Yes.
The Almost Due Invoices issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the Almost Due Invoices issue yourself by looking for a resolution described in the article. If it is a complex Almost Due Invoices issue or you are unable to solve the issue, you may contact us by clicking here or by using other Almost Due Invoices support options.
For more information about resolving issues related to Almost Due Invoices in Quickbooks/QBO or to get support for the issue 'I am not seeing any reminders for “Almost Due Invoices” on the reminder page.', click the link below: