In SharePoint Online, we have a document library of around 200,000 documents with a set of custom columns along with default columns like Name, Title, etc.
Searching files with some text, that is present in the filename, of some PDF files, no search results returned.
I have checked everything, Re-Indexed the Document Library, then Re-Indexed the whole site, wiatited for 4 hours, but it is still not returning results for PDF files. If we search for text on file names of other file types (msg, docx, xlsx etc.), results are returned, as expected. Only PDFs are having this issue. I am a site collection administrator; therefore, it should not be the permission issue
PDFs are not images but actual text PDFs we are just searching for text in the File Name field so it should return at least by matching file name.
Example 1 (PDF File)
PDF File Name: 45062-Customer Joe Blog.pdf
Search Query: 45062
Search Result: No Results
Example 2 (Docx File)
Word File Name: 45876-Customer Joe Blog.docx
Search Query: 45876
Search Result: 45876-Customer Joe Blog.docx (as expected)