Rotating the map images before generating will sometimes produce different results in terms of the amount of pages used in the PDF.
Test images:
https://drive.google.com/file/d/1k51giokNhMEZQA-tvPhU8WR6BRlkMLoN/view?usp=sharing
https://drive.google.com/file/d/1Kf6-v4oFF2WJ9JV0Fa4mmvNWdl7nViGa/view?usp=sharing