The original screen could briefly show the keyboard and then immediately lose focus. Its build method contained a request that moved focus away from the text field:
FocusScope.of(context).requestFocus(FocusNode()); The recorded behavior appeared after navigation through a MaterialPageRoute. A rebuild could repeat the focus-changing side effect, undoing the user’s attempt to edit.
The fix was to remove that operation from build and invoke dismissal from an intentional interaction, such as a button or background tap. A build should describe the interface without repeatedly fighting the interaction that caused it to rebuild.
This is a historical diagnosis. The newly created FocusNode in the old line is not a complete ownership/disposal pattern, and the original screen was not rerun for this revision.