On-premises SharePoint 2013 Enterprise Search Farm: for about 99.99% pdf documents (millions in the document library) search by Managed Property, CustomDocumentId (unique per doc), returns result. However, for a few, the similar query doesn't return results. Crawled history shows that document was crawled. Also, search by a different managed property like ProviderNumber finds the document. The property shows that it has a value. We can rule out the security as running queries as the Site Collection Administrator.
This works for most of the documents, but not for a few
CustomDocumentId:2E7AAA33-552E-A21B-14ED-11F423C14236
This returns the documents along with other documents
ProviderNumber:456734935983745
CustomDocumentId:"2E7AAA33-552E-A21B-14ED-11F423C14236"
=
instead of:
along with the quotes? The minus signs could be throwing things off. I second the opinion to use the Search Query Tool to help the troubleshooting.