Password screen: keyboard disappears when rotating the screen

This is related and sort of not related at the same time. I have the latest version of Textastic 5 (both the iPad version and iPhone version). Every time I launch the app, with the password protection feature of Textastic enabled, I have to be super careful not to rotate the screen. If I accidentally rotate the screen (on either version) the keyboard will not pop up anymore. Having searched for the previous version on the app store (and not finding it), I have no clue how I am supposed to get this issue resolved (besides dishing out another $9.99 for it). I am not a happy customer.