When you are waiting and you are asked to [そのままお待ちください], you are, of course, asked to continue to wait. But this expression is usually used in our daily conversation in the meaning 'Please wait just a bit (here)'.
It seems to me that in most cases or contexts, そのまま (without change, as it is, as you are) in this expression does not have a special meaning. I have listed some other expressions like this.
It may be possible to find the differences between these expressions. But the following point of view will be more important not only for you but also for me. It is very interesting to me that when a waiter comes to us and says「お待ちください」without some words before it, it may sometimes sound a little abrupt or impolite or even casual, though「おまちください」itself is a very polite expression. So we are unconsciously compelled to put some substantially meaningless words before 「おまちください」. This might be true of 'just' before 'wait here, please.'