Posts not having proper formatting, sometimes.

On my site, It’s Truly! Random! sometimes when I edit my posts the editor will format them funny. For example, a line in a paragraph will end before it should making it look something like this:

This is just an example, I’m typing this to show how sometimes
my site will show text funny, in a way that makes little sense.
Normally the text should only return
at the right edge but sometimes it does what is shown above.