Please format your code correctly following the guidelines in this post:
Otherwise we have to re-typed your code to edit it.
The problem is likely that the body exit call is never getting triggered. In which case, the problem is that your Player is part of the platform object and is no longer being detected as a separate body anymore.
Personally, I’d recommend not reparenting the Player. Then tell us why you are doing that - what problem does it solve? And let’s find a solution to that problem. Because fixing the problem you have now is going to be complicated and hacky.