The number is missing after merge two documents

Aspose.Words Product Family
1 
String path = "C:\\Users\\z_jia\\Desktop\\a\\DMS\\";
Document word = new Document(path + "a.docx");
Document coverWord = new Document(path + "封面0116.docx");
Document target = (Document) word.deepClone(false);
target.appendDocument(coverWord, ImportFormatMode.USE_DESTINATION_STYLES);
target.appendDocument(word, ImportFormatMode.USE_DESTINATION_STYLES);
word = target;
word.save(path + "output.docx", SaveFormat.DOCX);

I want to merge two documents and keep the a.docx format, I used the above codes.
but the results :

1920×819 111 KB

1920×832 114 KB

封面0116.docx (18.9 KB)

a.docx (2.9 MB)

output.docx (2.9 MB)

2

@GusGus The problem is not reproducible on my side using the latest 25.5 version of Aspose.Words for Java. Here is the produced output:
out.docx (2.9 MB)

Please try using the latest version of Aspose.Words and let us know if the problem still persists on your side.