Only Once, Stop On Trigger Exit check is not saved.

[minomod]

1. Only Once, Stop On Trigger Exit check to save the scene
2. Return another scene to the scene again
3. Only Once, Stop On Check whether Trigger Exit is checked or not
4. Only Once, Stop On Trigger Exit check is cleared.

[Tony Li]

That's correct. The Only Once checkbox only lasts for the loaded scene. When you reload the scene, the checkbox resets.

If you want to remember only once across scene changes, use a Dialogue System variable:

[minomod]

thank you. It's a very clear explanation