To produce:
Windows 11, with germnan localization (decimal comma, not decimal point)
Publisher 2.0.0, create a page with a frame text. Enter some text on several lines. Change the leading of a paragraph. Numbers 1, 2, 3 are correct. The intermediate numbers in the fly-out menue are displayed as 2.5, etc. When selected the Paragraph Lead was changed to 25. When typing the text 2,5 in the editor field the menue behaves as expected.
I suspect that the localization is not complete