we have a requirement to apply sensitivity label in all document in SharePoint site, to achieve that I follow the below steps.
1- create sensitive info type that detect all documents,
2- create auto labeling policy to apply the sensitivity label for all document contains the created info type.
the policy works perfectly and start labeling the documents , but many documents was not labeled. all none labeled document is XLSX and PPTX and I test the documents with info type test and all return as match.
i have no idea how to troubleshoot why the policy is not applied to some documents, and I opened a case with Microsoft support (Case #:28498740) and they were able to reproduce the issue in the test lab but they have no solution and they archive the case.