Clicking the red x is supposed to move it to the background, but in 11.5 it is closing the Reminders App completely. Other apps seem to be unaffected.
MacBook Air (2020 or later)
The red dot closes a document window, not put the app in the background.
However, if the app has no purpose in keeping running without a document window, the app may quit itself when the last document window is closed. In most cases, these are utility apps like System Preferences.
Apple apparently thinks Reminders has no purpose if you close the main window, so it quits the app.
The red dot closes a document window, not put the app in the background.
However, if the app has no purpose in keeping running without a document window, the app may quit itself when the last document window is closed. In most cases, these are utility apps like System Preferences.
Apple apparently thinks Reminders has no purpose if you close the main window, so it quits the app.
macOS 11.5 Reminders app closes with red x instead of go into background
