The global background is not being applied. (_global)

I’m a Glyphs 3 user. After creating the _global glyph and checking ‘Show Background’ in the View menu, the master background is still not visible in any glyphs. I really need the master background as a template to design multiple glyphs, but I just can’t get it to work. Please help me.

The “_global” glyph is a feature of “Global Glyph” plugin. You can get it from the Plugin Manager.