Emojis missing from Mojave

Old topic it seems, with various results in resolution: emojis do not display in the OS.

Whether in Messages, or in the keyboard viewer via the menu bar, they are represented by a blank box. It's like the font is missing.

Messages has "Substitutions--Text Replacement--Emojis" checked.

I restored standard fonts through Font Book.

I started in Safe Mode and had the same issue.