Missing option to create combining accents

I have a font that has no combining accents. Usually there is s grey lozenge to help you create these, but it is missing from my Glyphs (3.0.4 (3108)). Does anyone know how I can get this back? Perhaps this is a bug?

Screenshot 2022-03-26 at 18.06.01

The combining accents are in the language groups that need them.

Ah okay, thanks. Is this something that has changed recently or did I just have my wires crossed?

This has always been just a filter for the existing combining accents in the font. Which selection should it have show there otherwise? There are hundreds if not thousands in Unicode.