Different mono font line spacing

Hi, I have libreoffice installed on both my Linux Mint and Kubuntu system. I have wrote a 76 page document on Linux Mint, but then when I open it on Kubuntu somehow the document became 74 page long. I believe the difference is in line spacing of mono font on the last few pages of the document, that I saw quite different. The line spacing is 1.5, on Linux Mint it seems ok, but in Kubuntu the line spacing looks to narrow even though the line spacing of the document is still 1.5.
Any suggestion for this problem?

Have you the same fonts on both systems? Is there a substitution on one of them?

Is your document consistently formatted with styles only, without direct formatting?