Hi sh04565 ,
As this this document is created in different software, so the issues appearing while adding text box in the document is expected.You may try the KB article for Preflight tool for Fix-ups : - https://helpx.adobe.com/acrobat/using/correcting-problem-areas-preflight-tool.html
If it does not work, would suggest you to recreate the document in Acrobat Pro .
I've tried using the Preflight tool previously and to be honest I have no idea what I'm doing. I ran the digital printing fix and this is what I got which I don't know what it means. Also we can't recreate a document we get from other firms or clients because we don't have the source files. The reason this is such a problem is because we are relying on documents from a wide range of sources. We use those PDF files to incorporated into our documents and then use that as a final document. If we didn't need a digital copy we could print them all separately but that's not the case. As you can see this is a huge headache.
We are unable to reproduce the issue at our end. Could you please share one such bug file and exact reproducible steps.