Dock a split keyboard

Clearly you are aware of the keyboard-key at bottom-right of the keyboard - and how to use it.

To resolve your issue, begin by selecting Dock & Merge. The objective is to begin with the full keyboard docked to the bottom of the screen.

You will now have the full on-screen keyboard visible on the screen - and this will be anchored to the bottom of the screen. From here you can again split the keyboard…

Don’t use the keyboard-key to invoke the split.

Instead, simultaneously place two fingers on the keyboard (keys “f” and “j” are ideal) - and pause - before moving your fingers outwards towards the left and right sides of the screen. Your on-screen keyboard should split - and remain docked to the bottom of the screen.

From split-keyboard, you can return to a full keyboard using the keyboard-key - or, by using two fingers; place one finger on each keyboard segment, then slide your fingers together.

If your iPad isn’t performing as expected, try a forced-restart - as this will often clear an isolated issue:

Force restart iPad (models with the Home button)

Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.