Split screen Multitasking option has disappeared

Suddenly, Split View multitasking is no longer offered as an option when using my iPad Pro, v 16.1.1

Yesterday I was able to open a Word document, click on the three dots at top of screen, and choose a side-by-side split view option. I would then open a web document that would appear on the other side of the screen.

Today, when I open the Word file and click the three dots the drop box says “open another app.” The new screen pops up on top of the Word file. The only way to view them together is to use my finger to try to manually move them to different sides of the screen, but the screens are not stable enough to work with.

I have closed all of the open apps and rebooted the iPad Pro 11” second V. This problem first appeared using 16.1. I tried installing the latest operating version, the problem continues.

What happened? Any fix?