Long Press on "Back Button" doesn't force close Apps on new phone -- why, please?

[brasscupcakes]

Hi there, I am a long time Xiaomi phone user like most here and I am extremely attached to long pressing the "Back Button" in order to force close an app.
But this option is not working on the new phone I bought today (Redmi Note 9 Note).
I saw one other report of this in a forum from 2020 but it seemed to indicate this was a bug in Miui 12 and if it's a bug, wouldn't it have been fixed by now?
Is there a setting somewhere to enable this shortcut because I couldn't find anything?
Or perhaps there is an app that could "assign" this behavior?
(I don't think there is though -- I tried to program this behavior for a friend who asked me on an LG V35 and couldn't find any way to do it).
Thanks for any suggestions!

 

[Igor Eisberg]

Settings -> Additional settings -> Gesture shortcuts -> Button shortcuts -> Long press the Back button -> Close current app

 

[brasscupcakes]

Settings -> Additional settings -> Gesture shortcuts -> Button shortcuts -> Long press the Back button -> Close current app

Thank you so much! My menu hierarchy is missing the "gesture shortcuts" header but button shortcuts is still there. Really grateful, it's the one shortcut I can't do without!