Middle click "open all tabs" shortcut not working in bookmark submenus

v1.76.74

Currently when clicking with middle mouse button on a bookmark folder, it opens all the links inside.
This is correct behaviour.

But when you middle-click on a folder INSIDE a folder, then nothing happens.
Expected behavior:
Middle click on a folder should always open included links no matter how deep it’s in the folder structure.
Screen: https://prnt.sc/y3E-Vl0LtGo1

Duplicate thread: