I’m experiencing a problem I’ve never had on glyphs before. When I try to position the anchors on a diacritical sign (using cmd+u), nothing happens. This only applies on diacritics, not on letters. If there are already anchors on the diacritics, they are removed when I reposition the anchors (shift+cmd+U)
Also, when I try to place an anchor manually on the diacritics, it has no effect on the alignment of the components.
This happens on some my Glyph fontfiles, but not all of them.
I just double checked, and… indeed, it works with combined diacritics! I didn’t know that you can’t put anchors on simple diacritics. Is it new? It makes sense after all!
The Latin spacing marks (the ones without comb) are explicitly non-combining. For what you are trying to do, that is exactly what the combining non-spacing marks are for.