Numbers in exported font don't match master file

When I try to export the font via Glyph 3, the numbers size doesn’t match the original font file.

On the left is the original font.

What exactly did you do? Opened an existing installed font, made changes, exported and installed in with Font Book again?

  1. The installation preview of Font Book is not a reliable way of judging a font.
  2. This is probably a font cache problem. Read this please: Eliminating font cache problems | Glyphs