Block editor completely gone for second of two super user
tl;dr: Two super users in a blog network. 15 sites. When second user logs-in block editor is gone. I can see Gutenberg > Demo menu item, I can open “Welcome to Gutenberg Editor” demo page, but this page (as well as all other pages and posts in all 15 sites in entire blog network) is rendered using regular code editor. For first user everything works as expected.