Even in a group call created using the Invite Participant API, the ChatInfo remains null.

Teams user A initiated a peer-to-peer call with an IVR Bot, requiring ChatInfo details such as messageId and threadId. To access this information, we converted the peer-to-peer call to a meeting mode by inviting Teams user B. Initially, we successfully obtained this ChatInfo data from MS Teams notifications and the get call API. However, recently, the chatinfo is returning as null.

Response of Get Calll API:
{
"@odata.context": "https://graph.microsoft.com/v1.0/$metadata#communications/calls/$entity",
"id": "661f6800-3f84-4af5-8b20-967298e26d35",
"state": "established",
"transferState": null,
"terminationReason": null,
"direction": "incoming",
"ringingTimeoutInSeconds": null,
"subject": null,
"callbackUri": "---------callback url -----",
"requestedModalities": [],
"activeModalities": [
"audio",
"video",
"videoBasedScreenSharing",
"data"
],
"routingPolicies": [],
"tenantId": "#################",
"myParticipantId": "90735358-5b65-44bf-bcbf-cb5d485a9299",
"callChainId": "895569c1-385b-4245-8b73-21b403f896f4",
"mediaHostedRegion": "Unknown",
"replacesContext": "aHR0cHM6Ly9jYy11c3dlLTAzLXByb2QtYWtzLmNjLnNreXBlLmNvbS9jYy92MS9jYWxsUGFydGljaXBhbnQvNjI1ZmE0YjEtYjhkNS00MjgwLWI3NGEtYzk3OWUwMDdiYWIyLzEzL2szLzQyMS9yZXBsYWNlbWVudD9ydD05MWUxODU5N2FlMjY0NDgxYjkzYmVmNzMzMzg0MzQxMiZyYz1leUp5ZEdsa0lqb2lPRHB2Y21kcFpEbzFNalprTWpOaE15MWtNemcyTFRRM09UQXRZamc0TXkxa09ESmtORGd3WXpVeE5qUWlMQ0p5ZEd4cElqb2laVzR0VlZNaUxDSnlkSEp6SWpvaVJXNTBaWEp3Y21selpWQnliM2g1SWl3aWNuUndabk1pT250OWZRJTI1M0QlMjUzRCZpPTEwLTYwLTEzLTE3NyZlPTYzODQ0MzA5NDY2NzU2NDA3OQ==",
"resultInfo": null,
"answeredBy": null,
"chatInfo": null,
"transcription": null,
"callOptions": null,
"meetingCapability": {
"allowAnonymousUsersToDialOut": null,
"autoAdmittedUsers": null,
"allowAnonymousUsersToStartMeeting": null,
"allowTranslatedCaptions": true,
"allowTranslatedTranscriptions": true,
"entryExitNotificationsEnabled": null,
"allowRaiseHands": null,
"attendeeRestrictions": null,
"allowPstnUsersToBypassLobby": null,
"lockMeeting": null,
"disableLobby": null,
"allowTeamsMeetingReactions": null,
"attendeeViewModes": null,
"stagingRoomEnabled": null,
"cartEnabled": null,
"refreshCartKey": null,
"breakoutRoomsEnabled": null,
"meetingScenario": null,
"recorderAllowed": [
"Attendee"
],
"transcriberAllowed": [],
"copilotMode": null,
"allowLocalRecording": null,
"meetingLiveState": null,
"watermarkProtection": null
},
"meetingProperties": {
"instanceICalUid": null,
"iCalUid": null,
"meetingLabel": "00000000-0000-0000-0000-000000000000",
"meetingLiveState": null,
"invitedMediaGroupDetails": null,
"meetingStates": []
},
"breakoutDetails": null,
"pstnDetails": null,
"coOrganizers": [],
"toneInfo": null,
"terminationSender": null,
"mediaGroupDetails": null,
"recordingConsentDetails": null,
"mediaState": {
"audio": "active"
},
"callRoutes": [],
"source": {
"endpointType": "default",
"region": "uk",
"languageId": "en-US",
"countryCode": null,
"participantId": null,
"identity": {
"acsUser": null,
"spoolUser": null,
"phone": null,
"guest": null,
"encrypted": null,
"onPremises": null,
"acsApplicationInstance": null,
"spoolApplicationInstance": null,
"applicationInstance": null,
"application": null,
"device": null,
"user": {
"id": "****************790-b883-d82d480c5164",
"displayName": null,
"tenantId": "*****************e2f03",
"identityProvider": "AAD"
}
}
},
"targets": [
{
"endpointType": "default",
"replacesCallId": null,
"hidden": null,
"removeFromDefaultAudioRoutingGroup": null,
"participantId": null,
"id": "90735358-5b65-44bf-bcbf-cb5d485a9299",
"region": "uk",
"identity": {
"user": null,
"acsUser": null,
"spoolUser": null,
"phone": null,
"guest": null,
"encrypted": null,
"onPremises": null,
"acsApplicationInstance": null,
"spoolApplicationInstance": null,
"applicationInstance": {
"id": "##################7e34a1",
"displayName": null,
"tenantId": "###################e2f03",
"identityProvider": "AAD"
},
"application": null,
"device": null
}
}
],
"mediaConfig": {
"@odata.type": "#microsoft.graph.serviceHostedMediaConfig",
"preFetchMedia": [
{
"uri": "#########################",
"resourceId": "46c25478-88cb-4ca3-a85c-0e4850afc90e"
}
]
},
"meetingInfo": {
"@odata.type": "#microsoft.graph.tokenMeetingInfo",
"token": "#################"
},
"incomingContext": {
"sourceParticipantId": "91e18597-ae26-4481-b93b-ef7333843412",
"observedParticipantId": null,
"onBehalfOf": null,
"transferor": null
}
}

Response of Get Participants API:
https://graph.microsoft.com/v1.0/communications/calls/661f6800-3f84-4af5-8b20-967298e26d35/participants

=> Return 3 participants details which proves that call is group call i.e. no more p-2-p call

Expected Result:
ChatInfo should not be null. It should contains information like as sample below

"chatInfo": {
"@odata.type": "#microsoft.graph.chatInfo",
"messageId": "0",
"threadId": "19:5552c146-0b2d-4587-9e6d-350c61e62464"
},

Start by reviewing the Invite Participant API flow and the Get Call response for call 661f6800-3f84-4af5-8b20-967298e26d35. Compare it with the Get Participants response at /communications/calls/{call-id}/participants to confirm the call is in group mode. Done means the expected chatInfo behavior for this flow is established and the reported null response is resolved or clearly documented.