Text Editor blank space before text is trimmed

You still haven’t shown how the TextBlock is declared.

I’m assuming your listener code is actually:

  "TextEdited": function(e) { e.subject.text = e.subject.text.split(' ').join('\n \u00AD'); }

The \u00AD character is a “soft-hyphen”, so it should not be too surprising if you see a hyphen when a line is broken up into multiple lines. If you don’t want a line to end in a hyphen, don’t use that \u00AD soft-hyphen character.