OSK: continuous long press doesn't enter character
- Open GNOME Settings > Universal Access
- Enable the Screen Keyboard. (Optionally, turn on Always Show Universal Access Menu to make turning the Screen Keyboard on and off easier.)
- Open Text Editor
- Click the u button on the Screen Keyboard
- Long-press the u button on the Screen Keyboard for a few seconds. Keep the long press held and don't let it up until you have selected the ü character.
No character is output
- Long-press the u button on the Screen Keyboard for a few seconds until the pop up shows. Release your click then click on the ü character.