Pressing enter in the chat and game goes to fullscreen

[minecraft85lol]

/title

[Ad Bot]

[Marios]

It's because you're also using Alt while pressing Enter. It's a keybind that makes your game go full screen and can't be disabled via settings.

Try using Client_altenterfix (Paste to your Add-Ons folder) to disable the keybind.

[minecraft85lol]

Thanks it's worked.