Using Ctrl + LeftArrow/RightArrow to navigate to the beginning/end of TextBox will prevent you from typing.
How to reproduce:
- Insert a ScreenGui and TextBox in StarterGui
- Enter Play Solo (note, this occurs in plugins, too)
- Type some text (not necessary, this happens even if the TextBox is empty)
- Press Ctrl + LeftArrow to go to the beginning of the TextBox
- Try typing some text again. You’ll see that you can’t type text.
Where the bug happens:
- I only tried reproducing this in Studio. I haven’t tested what happens if you do this in a live game, but I suspect that the same thing will happen.
Video of the bug in action:
Roblox Version:

I am on Windows 10. I only have the Lua Draggers beta feature enabled.