We have looked at the major things that usually cause this.
I am trying to suggest things you can do to trouble shoot and zero in on the object(s) that are causing the display problem.
In the preview mode of the report, on the left hand side of the screen, just left of the ruler, you should be able to see the sections of the report and brackets indicating where they are starting, stopping or flowing over one page to the next. Look closely at this to see if you can determine if a section is actually flowing onto the next page or if it has stopped.
This should hopefully give you a cue as to what section or object may be causing the report to create a new page.
From there focus on that section or objects. Change the background color of an object to see if it is full of blank spaces that is making it grow but you are not aware of all of the extra content inside it.
In preview mode set one possible problem object to not grow. Dis that fix it? If not use ctrl+z to undo that change and then try another object. repeat as necessary until you see the extra page disappear.
try deleting the entire section you think is the cause then use ctr+z to undo it. This can help you at least verify otr narrow down where you need to look for sure and not chase false leads.