In FactoryTalk View SE events have to be turned on. Then if you make a change, you have to turn them off and then back on to see the change. Typically these events are turned on when the HMI Server machine boots up. But not always. It depends on how the programmer decided to start it.
If you can access the Command Line in Studio you can click on the ellipses button on the right (button with three dots) to access the Command Wizard which will walk you through starting your Event file.
If the event file has been started but is still not working then access the event file and grab a screenshot of the expression and action for the event you are after.
OG