Nothing was attached. If you can please attach a sample document with three paragraphs: one from before it changes, one after, and one more after.
Attach a Sample File Demonstrating the Problem - Here's How

When you are looking for help, jargon can be important.
There is no such thing as normal paragraph formatting as such, but there is a Normal paragraph style, which does contain paragraph formatting.

1. Use Body Text Style Instead of Normal Style
2. The Importance of Styles in Microsoft Word