We could see two different issues in Word to PDF conversion modes.
1. EnableFastRendering mode: OutOfMemoryException is thrown while converting Word to PDF document.
2. EMF mode i.e., disabled EnableFastRendering: Preservation issue is found in the generated PDF document.
We have found that the preservation issue and exception occurs when processing high pixel image in provided input Word document. On further analyzing, we also found that the reported issue occurs only in x86 bit .NET Framework due to less memory allocation when compared with x64 bit framework and so it works properly without any issue in x64 bit framework. Kindly change the .NET framework settings to x64 bit to resolve the preservation and exception issue on converting Word to PDF conversion. This is not an issue at our end.