Anchor propagation fundamentally broken

Hello, for a few versions now, anchor propagation is broken, meaning: anchors inside components aren’t recognised in their composites. When decomposing the component, the anchors don’t appear.
An example, glyph six:

I have the six as a component in nine (don’t spank me). When I use nine elsewhere, the _center anchor isn’t recognised:

Furthermore, decomposing the component six in my glyph nine doesn’t produce the anchor:

This is frightfully annoying and has been driving me various species of nuts, especially since this worked in earlier Glyphs versions.

Can you send me that file?

Sent. Pretty much the same file as last time.