Missing chunkFinished CallRecordingEventMessageDetail change notification

Question

Hi all,

Currently building an app that receives chat and channel change notifications and I am interested in getting the callRecordingUrl. From what we understand, the only time a downloadable resource is made available to us is when it is sent to us via a change notification that contains a calRecordingEventMessageDetail with the callRecordingStatus "chunkFinished". However, we have observed that the chunkFinished change notifications do not always get sent to our app. We have ensured that the subscriptions are all alive when this happens and we receive chatMessages that contain callRecordingEventMessageDetails with the "initial" and "success" callRecordingStatus, but never get the chunkFinished message that contains the callRecordingUrl that we need.

Is there any reason the Graph API will withhold the message with the chunkFinished status? Also, is there another way to get the url? We understand that there is a url provided by the "success" notification to OneDrive where we might also get the mp4 file, however, we do not know whether that is an option we can use due to the additional credentials being needed.

Thank you