Tips for Embedded reports:
Remember that embedded reports are used across the platform as part of the user interface, such as the course catalogue page. So if you edit an embedded report, it is always live and available to other users.
If you are editing then you have a couple of options to do this safely:
Use the clone report feature to make a duplicate of the report
Use the restore default settings option if you edit the live report and are unhappy with your changes
Add filters to sort data out quickly