I don't understand what these faint yellow lines are and how to turn them off (see screen shot). I have created toggles from a prefab and to save time have been duplicating them and moving them. Unity chugs everytime I move a group of them, and I imagine it is because it is recalculating how to draw these lines. All of the toggles have lines between them. Send help!
eg. If the player currently has UI widget A in focus, and presses the right arrow key, which UI widget gets input focus next?
You can click the "Visualize" toggle button in the "Navigation" section of the UI component to turn these arrows on or off.
You can also disable automatically computing navigation links entirely by setting the navigation mode to None (for no directional button navigation) or Explicit (to specify the next UI element in each direction yourself, in the Inspector). Note that directional navigation is important for accessibility (eg. for players with lower visual acuity or motor precision), so I'd recommend ensuring your UI is still navigable in this way.