usually, double tapping recents key should switch to next/adjacent app in the task manager in any phone, but not in Zenfone 9. Often double tapping won't switch to next app, rather will switch out and back to same app, sometimes will go to homescreen. Sometimes, if recent key is double tapped multiple times quickly, the key freezes and home key needs to be tapped to unfreeze it.
Double tapping recents to switch between apps is slow in Android 12 onwards, which google's fault, but at least in other phones it works, be it slowly. But in Zenfone 9, it doesn't even work vast majority of the time.
It doesn't seem to occur if Animator duration scale" is set to 0 or off, but who would use a phone like that? In the end it's a bug which Asus needs to fix quickly.