Hello,
Thank you for posting in Q&A forum.
To fix this issue, please kindly try below steps:
1.Go to Excel Trust Center Settings, and add the SPO site to trusted in the browser or via GPO for all users. You need to make sure “Check Microsoft Office documents that are from or link to suspicious Web sites” option is properly configured.
2.Go to Internet Options -> Security -> Trusted sites and add the SPO site to check if it works.
I hope the information above is helpful.
If you have any questions or concerns, please feel free to let us know.
Best regards,
Jill Zhou
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