In Preview you can turn on or off automatic highlight/underline/strikeout by clicking the 'pen' in the "highlight" item in the tool bar. The keyboard shortcut for this is ⌘ Command^ Control H/U/S, typed when nothing is selected.
What is the keyboard shortcut to turn off automatic highlight/underline/strikeout?
Best Answer
To turn it off, you have to go back to "text selection mode" but unfortunately, there's no keyboard short cut. From the Tools menu, you would click on Text Selection to get out of the automatic highlight/underline/strikeout mode.
However, we can create one!
In System Preferences → Keyboard → App Shortcuts create a new shortcut by clicking the "+". Then, in the drop down, select "Preview" for the App, type the exact name of the menu title, in this case "Text Selection" and assign it a shortcut. I used ⌘ Command^ ControlT to stay consistent with the other shortcuts.