You can check some below pointers to troubleshoot your scheduled reports:
A new scheduled report does not arrive
If you have scheduled a report for delivery but do not receive it, one or more of the following can contribute to the issue:
The recipient's email inbox or FTP destination is full.
The recipient's mail server is down.
The recipient's spam filters are errantly flagging the scheduled report as spam.
The email address specified in the scheduled report contains a typo.
If using data extracts, ensure that the report was explicitly scheduled (they are not by default).
If using data warehouse, ensure that the date range in question is not in the future.
To determine if this issue involves Customer Care, add an email recipient outside your organization's email network (for example, Gmail, Yahoo, or Hotmail). Then, at the next scheduled delivery time, do the following:
If you receive the scheduled report at the new email, work with your organization's IT team to troubleshoot and determine the root cause of the issue.
If you do not receive the scheduled report at the new email, have one of your organization's supported users contact Customer Care for further assistance.
An existing or long-standing scheduled report does not arrive
Go to Components > Scheduled Reports and click Report Queue. Click 'Show all scheduled reports' to see what is processing.
If there are any reports processing ahead of the specific report you are expecting, you can use the up/down arrows to prioritize your report.
If your scheduled report has a red error icon next to it, try rescheduling it. Sometimes server maintenance can cause temporary issues with scheduled reports.
If rescheduling reports continue to fail, re-create the report manually and schedule it. If segments or calculated metrics are deleted when used by an existing scheduled report, it can cause the report to fail.