Acrobat Pro DC - Image gets puzzled (split into pieces) upon "Edit PDF"

[batjaa]

Architecture: x86_64

Build: 20.13.20064.406117

AGM: 4.30.104

CoolType: 5.14.5

JP2K: 1.2.2.46820

I have a .pdf file that has an image that fills the entire document. Think of it as a pdf file that has just 1 big image. When I open Acrobat Pro DC and select - "Edit PDF" - select my .pdf file and open it for edit, the image gets split into several squares/rectangles as if they are all separate smaller images. It becomes something like a puzzle. If I save it as a JPEG then the final jpeg file shows a small gap between these puzzle pieces and they are not stichted/merged together perfectly as they were in the original pdf file. 

My guess is that the OCR is somehow detecting the single image as several smaller images and breaking them into pieces. The reason I saw that it if I use online tools such as https://smallpdf.com/edit-pdf to edit the pdf I don't see the image getting split into smaller pieces like Acrobat Pro DC. So a few questions:

1. Is there any OCR setting to tell it not to break imake into smaller pieces like this?

2. If it is not the OCR, what could be the reason?

3. How can I prevent this from happening such that when I edit this pdf I just get 1 image? 

[Luke Jennings3]

I suspect the image was fragmented in the application that produced the PDF, if your on-line pdf editor appears to be editing an unfragmented version, it may just be seeing the combined fragments, can you save an image from your on-line PDF editor? Can you try re-creating the original PDF, without flattening the PDF and choosing a recent Acrobat compatibility? (Acrobat 7 or newer). If that doesn't help, you can try running an Acrobat Preflight fixup to combine the fragments. Other options are to open the PDF in Photoshop and save as a high res image (tiff), then place the original PDF onto InDesign (with the original image deleted) and the new (edited) image in its place, exporting to a new PDF. Or, extract all images in Acrobat- Tools> Export PDF> Image (tiff)> Extract all images.

FYI, you can determine the source application of a PDF by going to File> Properties> Description, in Acrobat.

[JR Boulay]

You can use the PDF Optimizer too.

[Sandra23674580mkz3]

I think it depends on the Presets used when the pdf was created. So far, if I use PDF/X-1a, when I edit the document in Acrobat, the images show as squares while it doesn't happen when I export the original document using Press Quality.
Hope it helps.

[JR Boulay]

When exporting to PDF choose version 1.5 or later (1.6 or 1.7), then transparenties will not be flattened and images will not be sliced.

So, no PDF/X-1, prefers PDF/X-4.