Weird shift with composites

Hi, here is something that caught me completely off-guard: diacritic marks get shifted vertically when they are used in composite letters. Everything put in the box gets shifted one alignment zone (14pt) up.

How can I fix it and what did I do wrong?

Glyphs 2.1 v.767
It so happens that the alignment zone and the stem are the same width - a design decision .

Can you send me the .glyphs file (to support at this domain)?

I had the .top anchor at the wrong place. Everything is fine now. :pensive: