Problème d'alignement et de césure

It looks like you are missing a space after the comma

passé,plus is being treated as a single word. Adding a space after the comma should fix the issue.

The difference between Justifed and Aligned left is likely due to the Balance Ragged Lines box being checked. 

THe block changes because of the Keep options and Justification settings in the paragraph style. The spaces are not equal in both. You have a variation. In the first line goes InDesign to a more condensed space, because otherwise only a partial word would be in the next line. If you make a left, centered or right InDesign uses the optimal value.