I am using ArcMap 10.5.
I created an excel spreadsheet with fields and lat longs that I used to Add XY Data, convert to shapefile, label, then convert labels to annotation stored in the map document. The projection of the annotation class matches the data frame.
If I make changes to an annotation by focusing the Data Frame, and double clicking an annotation to get to the properties box, I type in what I need, but it doesn't display properly in the map. Text ends up stacked on top of itself, and the multiple lines of text become one long line of text. Please see both screenshots, they show the text properties box, and how the text actually appears in the map.
I have used this same shapefile for annotation in another map and it worked fine. Not sure what is going on in this map.