When trying to edit UI actions on a form in Internet Explorer, the Edit UI Action context menu is hidden behind the form header and only a very small portion of the button is displayed.
In Google Chrome, right-clicking a form button on the top of the form does not render the Edit UI Action context menu.
Users can right-click on the buttons at the bottom of the form. These are working and will show the Edit UI Action option.
Users can also right-click the form header and select Personalize > UI Actions from the menu.