On 2024-04-16, The Wanderer <wanderer@fastmail.fm> wrote: > > What needs to happen, according to that analysis, is to close one of the > windows not by File -> Exit or File -> Quit, but by File -> Close. (In > my - severely obsolete - Thunderbird version, it's near the top of the > File menu, and has the associated keyboard shortcut Ctrl+W.) > Yes, that's the "solution" I attempted to describe.