Just press and hold on one of them and you'll get some options to close the tab, start a new tab, or merge all tabs. Press and hold the Sleep/Wake button (Power button) until you see the slider, drag the slider to shut down your device and then press the same button to turn on your device seconds later. I had to completely shut down my iPad and restart it and that got rid of the split screen. Secondly, search for tab resizes extension in the search bar.
It's a gray app that contains an image … Splitting your screen is excellent for doing research, looking up tutorials, consulting multiple sources, comparing images or video, and much more.