@Viktorija ,Based on my checking, for the Microsoft Defender Antivirus report, it gets the report via "Get deviceManagementCachedReportConfiguration".
For Antivirus Summary under Endpoint security, it gets the information from deviceManagementConfigurationPolicy,
From your description, it seems the information in two sides is not the same. To check on this, we need to check in the background. Here, we suggest to open case to look into it. Here is a link with the detailed steps to open case:
Thanks for your understanding and have a nice day!
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.