Course re-entering on a specific slide after exiting, then re-entering during UAT testing

Hi ,

I wondering if anyone has encountered this problem and if you have any suggestions.

We are experience an odd but where when a leaner exits our Storyline 360 build from any point then tries to re-enter, they re-enter on a s specific slide. Irrespective of how far they have gone into the eLearn. Following are the details.

Build: Storyline 360
LMS: Success+

When: in UAT testing
Bug: when the learner exits at any point in the course then re-enters, they re-enter on a specific slide in section 3 of the course.

Questions:
Is it possible that we have accidently set this up in a setting somewhere?
How do we fix this problem?

We need to fix this urgently.

Thank you!