I would place a service call, as it would appear there is an issue with your device.
I tested our device, scanning 3 pages (double-sided) to a B&W, searchable PDF format. One scan had a lot of graphics and another was mostly text. The graphic document scanned and processed in 54 seconds, the text document was 34 second, timed from the press of the start button, until the job showed completed on the local touch screen.
Both of the sample documents, can be printed from the local control console of the WC58xx device.
The amount of time it takes to ocr 1 document is obserd. I timed a 5 page document and it took 15 minutes to ocr it. Bran new copiers and they are slow as molasses something needs to be done about the speed of this if not just remove it from them because as it stands it is unusable because it holds up all the other jobs.