Rise 360 xAPI passing PTNaNS as duration

Hi, we have many clients using our Rise courses which are communicating with our LRS via xAPI. All of the courses are working for the many of users. But there is one course, and one user where an attempted statement is being sent with a duration of PTNaNS, Not A Number error. No other users have this issue on the exact same course? And this user doesn't have any issues with any of the other courses we have created that are attached to the exact same LRS with the exact same credentials passed in the course url?

There is a PUT call to the statements endpoint that is passing an attempted statement and the duration is NaN. With other users in the same course it is a valid number i.e. "duration": "PT2M27.725S".

The LRS returns a 400 error:

{errorId: "e43c5a06-9a6a-4dde-af9d-0c00d103c96c",…}
errorId: "e43c5a06-9a6a-4dde-af9d-0c00d103c96c"
warnings: ["Problem in 'statements.0.result.duration'. Received '"PTNaNS"'"]

I would rather not post the url as it has student data attached to it.  Just wondering if anyone has seen this error? Or knows why only this user is getting it? And what I can do to fix it?