Using the newest update of MIUI (12.2.4.0, installed today) the menu (recently opened apps that are still running in the background, accessible through rectangular android control button at the bottom of the screen) only shows the background picture of the home screen but not the opened apps.
That means that I can't change between my opened apps anymore but need to always go back to start screen and open them manually again.
Changing to the default launcher of my device (Poco F2 Pro), the Poco Launcher, the menu works just regularly.