If you have an iPad Mini and you notice that tools are missing from the toolbar when editing or viewing your Notebooks in portrait mode, it is because the toolbar is 'swipeable' on these devices.
Most commonly this happens on smaller iPads, especially in portrait mode, or when you use GoodNotes in split screen.
As the toolbar is "swipeable," it means when some tools are not displayed or not correctly displayed in the toolbar, you will need to swipe through the toolbar to reveal the missing tools.