I get a black box with white border over my keyboard on my iPhone 15 Pro Max

I get a black box with white border over my keyboard on my iPhone 15promax. FYI - I have updated my iOS to 18. What is this box? Why is it repeating what I type? How can I remove it? It is very annoying.

1. When I search anything on my phone it duplicates what I type into the search box.

2. When I took screen shot it appeared on the screen as well. Thus messing up the screenshot.

3. When I type ‘s’ in my search, besides repeating it, it vanishes my search. That is nothing is searched but Siri suggestions appears.

[Re-Titled By Moderator]