Second export of caps goes strange

When I open the attached font in glyphs and export it, things are fine:

When I export it a second time, the cap goes wonky:

Here’s the file: (1.3 KB)

Works fine for me.

Usually it is advised to not have the origin and the first node to overlap. The vector between the two is used to calculate he direction. Either move the origin down a bit or add an ‘left’ anchor.

And I would move the origin down to the base line. That way, you have the path in the ‘a’ sitting on the base line, too. That helps to make it consistent.