I also note a number of differences. The formatting may look the same in the two documents but is not.
I literally copied the style and just renamed it.


Copy and paste in original document: pasted text is same.
Same thing happens with new document; pasted text is the same.
Odd. Do you see the screenshot? That's what is showing up on mine.

In neither case is there blue or a change in the font.


Any chance you've different paste behavior options in operation? No, same, just right click and copy and paste. I tried it multiple times among the two documents. Even tried doing a save-as of the new document a few times and those didn't stay either. Only the original stayed (with the unchanged style names) remained correct.





This is a Word setting rather than a document setting. Yes, so how do I fix it? It looks like it's reverting to default Word settings.

No one is accusing you of anything. We are telling you what we see. Just him, no one else was doing that.