Weird Copy Paste UI comes when copying anything and existing in structure block and Jigsaw block

Summary:

A weird copy-paste UI seen when the player uses structure/Jigsaw blocks to copy texts then immediately exit the UI screen by using button.

Steps to reproduce:

1. Open existing world or create a world with cheats active
2. get structure block and jigsaw block
3. Click to open UI 
4. write something in structure block or in jigsaw block
5. Copy written text
6. Immediately click exit button

Observations:

You will see that a UI pop-ups usually in black-green colour on top left of screen, it behaves as any text is selected and there were a 3 dot button and some other buttons, nothing will happen if clicked on appearing copy-paste UI.

Expected results:

It is expected that their should be no UI appearing after copying any thing in jigsaw and structure block UI and immediately existing the UI from button