OneDrive no longer creating functional iframe sharing links

Your permissions may be correct, but a view-only sharing link is not automatically a valid Excel embed source. Regenerate the iframe using Excel for the web’s Embed action rather than copying the normal Share link. For a work or school workbook, first confirm that the sharing link opens in a private browser window without an unauthorized sign-in request. Then create embed code and test it on a minimal page before restoring it to the original site. If private access fails, the tenant’s external-sharing policy or link type is the blocker. If the workbook opens directly but the frame stays blank, check whether the host page blocks Microsoft 365 frames through its content-security policy, and test without browser extensions. Because several embeds stopped together, check Microsoft 365 service health. If generated code also fails on a minimal page, open a support case with the tenant, workbook URL, and failure time.