When I add a period component, it sticks to the bottom of the question component. Since there’re no anchors in a question glyph and automatic alignment is off, it seems like a bug.
Glyphs didn’t tint the period component with a greenish shade, but under the hood the period had Automatic Alignment turned on. That’s why it has been sticking to the bottom of the question.
Mekkablue’s Alignment Manager script helped with turning it off and splitting the question and the period components off.