I have a very simple test where I am opening DOCX document. Enable track changes and inserted some text with user comments and saving it. When I try to open the output document some pages are missing.
A sample project is attached.
Track changes.zip (9.0 MB)
The input document should have track changes ON.
The input document should have user comments.
The input document pages are more than 50.
Please let us know if you need more details.