Some thoughts:

- if you get whatever you wanted before it snaps back out of it, wouldn’t you say you had a successful jailbreak?

- related to the above, some jailbreaks in physical devices, don’t persist after a reboot, they are still useful and called jailbreak

- the “snapped out”, could have been caused by a separate layer, within the stack that you were interacting with. That intermediate system could have detected, and then blocked, the jailbreak