Issues with margins and text wrapping

I’m experiencing some weird problems with text wrapping. See pic

. This is in a research text box with everything set to defaults (and all the defaults I could find reset multiple times in an attempt to solve this problem). Part way down, the text starts wrapping early. Everything here is typed directly into this text box except the bibliographic info which I pasted from where I’d typed it into another default text file bibliography. Only invisible characters appear to be carriage returns at the end of paragraphs, visible when highlighted. Highlighting is sticking to appropriate margins, but text wrapping is not. Any idea what I’ve done or how to make this stop happening?

Thank you!

Have you looked at Format>Paragraph>Tabs & Indents? Any styles set? You could try selecting the document in the Binder and go to Documents>Convert>Text to default formatting.