Really common misconception that every RODI unit is equipped to remove chlorine/chloromines from municipal water supply. Very few are, and if your carbon manufacturer doesn't state it, chances are the majority of them are getting through - this is why I still dose my RODI water with Aquavitro Alpha. BulkReefSupply covers this topic very well, see the video below.
https://www.youtube.com/watch?v=tEL8KvDr3-k