I read that there may be rooms in this puzzle not on the maps. I have found several secret room but wonder if there are rooms not shown as secret on the maps?

What I meant when I said that was:

Some of the secret rooms are not visible on the Map (until Jack has found them, at least)... which I have programmed like this to make the hunt for the secret rooms even more difficult and thus - more thrilling and entertaining.

It does not mean that there are (secret) rooms which have not been marked as "secret" and would therefore not raise your "secrets count".
It has nothing to do with that.

Clear enough ?    8-)   :-/

This feature to have rooms not show up on maps (until found) has been around since the beginning of MM and is in fact used in some of the included mansions.