How to fix split screen not working on iPhone with iOS 26.2.1?

I have the latest iOS update (26.2.1) but split screen doesn’t work. The three colored dots do not appear. The only reason I knew they existed is because my wife’s works.

What’s the fix?

This adjustment is not an improvement. It just makes the task more complicated. 🤦🏾‍♂️

[Re-Titled by Moderator]

Original Title: Slip screen doesn’t work