I have this situation where the dotbelow is far on the left:
When there is an anchor with and underscore or outlines (both apply here), Glyphs will not look further for anchors. So the ‘i’ has no bottom anchor.
I see, but why is it locked to the left position?
That is a good question. I have a look.
But you should fix the composition anyway. I would put the dot-path in a glyph called
dotaccentcomb.i. Then the component can be auto aligned.