Storyline: video does not play and keeps charging

Hello! 

One of our  clients bought around 60 licenses for an e-learning and those who started it made it to the end and retrieve their certificate EXCEPT FOR 1 USER.

He's one of the administrators of the firm (high profile) and he's stuck on a section where he has to click on "Start" and a video plays automatically. 

The video does not play and instead the content is on loading mode with the 3 dots charging. 

I personally tested the elearning 5 times since yesterday on different browsers and was not able to replicate the issue. Plus, his colleagues from the same firm did not have the issue. 

Do you guys think it might be an IT restriction from his side since he has a higher profile? What else can I check or suggest? 

Thank youuuu