See the attached screenshot.  I added the image at "Fit to Page" size but the top of the castle is cut off: as you can see by the selected thumbnail on the left.  That's because there are two cropping methods in Qimage where you give Qimage permission to crop: (a) to get the exact size you chose and/or (b) a previous manual crop created by you.  Both are chosen by you, the user, so...

Just make sure the two cropping methods are turned off if you don't want any of the image cropped: see attached.  Select the print on the live view first and then turn OFF automatic cropping (arrow #1) and then turn off manual/user print cropping (arrow #2) if it exists - click on the cropping icon on the print if one exists and you can remove any manual cropping.

Once you do that, the entire image will fit on the page even if you click "Fit to Page" after that.  Just be aware that if you choose to not crop your image at all, it may not fill out the entire page (or chosen size), because it can't without cropping.

Regards,
Mike