Case: Launch Print preview (first time), confirm dialog "Auto fit drawing to paper?" with yes, change after that the scale, close Print Preview, launch Print Preview - the last chosen scale what should be remembered is overwritten by the Auto fit scale.

Note:
The Auto fit scale stays persistent - even after reloading the drawing!

The option "Auto fit drawing to paper?" as a dialog occurs only the first time you use Print Preview - there is no way to change the chosen option later in a session or after reloading the drawing ...