Did you double check all the prerequisites?
- The accent (e.g.
acutecomb) must have the underscore anchor (e.g._top). - The base glyph (e.g. the letter or preceding combining accent must have two or more corresponding base anchors, alternates with underscore suffixes (e.g.
top,top_1,top_2). - In the compound glyph, the anchor alternatives should appear if you click the accent component (in this example, the
acutecombcomponent).