The latest version of Zen Browser added a new feature that keeps all instances of the browser in sync. That means when you open up two different windows each tab will stay in sync, so it’s really hard to have different content in two different windows.

Yes it’s on by default, and no they won’t change that. Fixing this means a trip to about:config where you need to find zen.window-sync.enabled and change it to false.

Then restart Zen for it to become usable again..sort of. Setting it to false also breaks a new window via CTRL N and it just opens blank. So I guess I adopt their workspace view or find a new browser.

The Zen team has a different view of how you should use your browser. When you open a new window, use a different workspace which will sync. With two instances of the browser in different workspaces I guess this works, but I’ve never used by browser that way which means their new setting changes how default web browsers have always worked.