I'm playing on the 1.11.0 version of All of Fabric 6, and when I alt-tab out of the game to check the wiki or something, it doesn't pause and just keeps running, instead of going to the esc screen.

hold F3 and press P to toggle pause on lost focus

hold F3 and press P to toggle pause on lost focus

Obviously, I already did that.
My bad, I was going to say that, except I first accidently almost posted this on the AOF 7 page, and then I forgot.