Same problem here (iPad Air 2, only a year old, not old technology).
when you go back to home screen, either with home button press or four-finger gesture, the dock first shows only the standard app icons (or ones that have been explicitly, manually placed). After a few seconds, the dock adds the machine learned app icon with an alarm badge and “slides over” so as to keep the dock centered on the screen. The time between positioning a finger to select a docked app icon, and actually touching the screen, is enough time for the dock to recenter itself, thus, you wind up selecting the wrong app icon and opening the wrong app.
its a UX bug and we hope developers fix it soon.
the fix is either one of two things: first, allow option to completely disable the machine learning app icons in the home screen dock; second, do NOT auto-center the home screen dock, especially when machine learning is enabled.
PS: to answer other posts, turning the device off, then back on, will make the machine learned app icon go away completely but only for a 24-hour period; it comes back the next day. At least restarting a device is a good thing because it keeps the file system cleaned and flushed 😒