Pressing Backspace while renaming an item inside an Anvil doesn't work

How to reproduce bug:
Place an anvil and get any item
Right click on it and try to name it anything
Press backspace or try selecting the text using Shift + left/right arrow key

Expected behavior:
Pressing backspace would remove text

What happened:
The text wasn't removed

In the video below, I try to rename a sword but fail because of this bug.

So apparently this bug is already fixed in "a future update", i made this report before i found that out so just ignore it