Stem Break (Glyphs 3)

Glyphs
1

Hello
When I draw a stem from two shapes/component/mix, it breaks a bit as it shown:

image
image830×772 42.3 KB

No matter what are those two shapes are (2 components/1 components and 1 outline/2 outlines) the result is same. Example:

image
image364×260 21 KB

The only solution that works is to make it one shape. Is there a solution to make it 2 shapes and works without breaks?

2

This happens when interpolating from different origins. Make the top part a component, too. make sure that the top path (inside that compound glyph) is horizontally at the same position than in the other component.