I updated version 1.75 to 1.80. The update offered itself, I did not download anything, I entered the license key and e-mail and confirmed. Then the installation took place.
I did not reinstall the downloaded version 1.8, only the older version 1.75, the update offered itself.
To the different font size I should add that it occurs on one PC, on another laptop is the font correct. I guess you can't help me with that. The text Configure Start10 ... it also has a larger font. The operating system is the same Windows 10 Pro, version 1909.
But I don't want to burden you unnecessarily.
EDIT 13.12.2019: If you overwrite "start10_64.dll" in the installed version 1.8 with the same file version 1.75, the font of the submenu will be fixed.