Number of participants is reported inaccurately on CallRecord endpoint

We have been pulling CallRecord data via Graph API for analysis. One particular record grabbed our attention.  According to the JSON return from Graph API there were 40 participants and 60 sessions. However, the online CQD dashboards showed over 120 participants for the call. 

So we started to troubleshoot and noticed that our logic does not support the session "nextLink" and there were more than 60 sessions for this group call. We fixed it; so now we can support the pagination. However, the "participants" array field in the JSON return still shows 40 participants. We checked all the returns from Graph API. Only the first return that we made against the call-id has the participants section; the rest of the paginated returns for session does not even have a participants section. They only include the session and segment info. I think subsequent returns do not even have the stream metric details either.

So is this a expected behavior? Do we need to call the link in nextLink section differently, so that the return includes all the participant data?

Thanks