The trouble is that it all depends on the moistening of the atta; if too much, it doesn't hold up to rolling, if too little, it will form rotis, but is liable to get hard on storage.
You clarified that it is not a problem with the rotis being hard, but with them being rubbery. Apparently, you are saying that the rotis become difficult to tear and eat.
Try mixing a bit of milk in the dough? You might have to experiment, using a tiny portion, and gradually increasing it, until it reaches the balance you want.
Most likely reason.
Also, too thick to heat through, remains 'kachcha' inside?
You really know how to hurt a guy.