Clicking outside of a user tour dialog exit the tour (regression)

On latest Moodle 3.5dev (master) and qa.moodle.net, clicking outside of the current step dialog window, closes the dialog and stop the tour. it seems like a regression relating to Moodle 3.3 stable (we are currently using).

It's an issue, since we frequanty ask the users to input some text in the various forms, and we need the tour step dialog to still be open on top of the page and not disappear, so the user can continue the tour after she/he finishes updating some form fields.