Hi @Norman,
Welcome to the Microsoft Q&A forum.
Thank you for contacting us. I would like to provide you with the following information:
Since you have already tried the troubleshooting methods but the issue still persists, in this case I recommend that you create a support ticket with Microsoft’s technical team through the Microsoft 365 Admin Center.
Once you create the ticket, a Microsoft technician (live agent) will proactively contact you and assist with an in‑depth investigation of the issue.
To create a support request, please follow these steps (note: admin permissions in the tenant are required):
Step 1: Go to admin.microsoft.com
Step 2: Select Help and Support
Step 3: Enter the title: Support to check the Schedule Send feature
Step 4: Click Contact Support
Step 5: Choose the preferred contact method
After completing the steps above, a Microsoft technician will proactively reach out and help you with the detailed investigation.
I hope the information above is helpful. If you have any additional questions or need further assistance, please reply so I can continue supporting you.
I look forward to hearing from you.
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