[PsiBot Example] Bot call getting deleted automatically after getting established.

We are trying to solve for a business problem, where we need to generate real-time captions/transcript for an ongoing teams meeting. For this I am using PsiBot example. I am trying to set this up first on my local following steps described here https://github.com/microsoftgraph/microsoft-graph-comms-samples/tree/master/Samples/PublicSamples/PsiBot.

When I try to join the meeting, as soon as call is established it is deleted with error message "Server Internal Error. DiagCode: 500#1203002.@".

I found a thread with similar issues here "https://github.com/microsoftgraph/microsoft-graph-comms-samples/issues/828" and have followed suggestions provided by ssulzer but no luck.

Sharing below notification message that I got as part of "Deleted" call. Please let me know if more details are needed I will be happy to help:

Accept: application/json
Accept-Encoding: (redacted)
Authorization: (redacted)
Host: 6d6b2eb931f6.ngrok-free.app
User-Agent: Microsoft-Skype/3.0,(Calling/1.0)
Scenario-Id: 9bc666c4-6902-49fb-be32-5a2cb202e9da
Traceparent: (redacted)
X-Forwarded-For: (redacted)
X-Forwarded-Host: 6d6b2eb931f6.ngrok-free.app
X-Forwarded-Proto: https
X-Microsoft-Skype-Chain-Id: fcecd617-77b5-4e5b-81d1-15f3f15f49a6
X-Microsoft-Skype-Message-Id: 9872d750-4b1b-4d9f-aee8-66501bc0f7ed
Content-Type: application/json
Content-Length: 979
{
"value": [
{
"changeType": "Deleted",
"resourceUrl": "/communications/calls/06004580-2a58-4f6e-a599-e7361515ee21",
"resource": "/app/calls/06004580-2a58-4f6e-a599-e7361515ee21",
"resourceData": {
"@odata.type": "#microsoft.graph.call",
"callChainId": "fcecd617-77b5-4e5b-81d1-15f3f15f49a6",
"chatInfo": {
"@odata.type": "#microsoft.graph.chatInfo",
"messageId": "0",
"threadId": "19:meeting_OTc1YmY3NzgtZTE2ZS00OGIzLTkwMDYtYzNhODZlNjNjMWU1@thread.v2"
},
"meetingInfo": {
"@odata.type": "#microsoft.graph.organizerMeetingInfo",
"organizer": {
"@odata.type": "#microsoft.graph.identitySet",
"user": {
"@odata.type": "#microsoft.graph.identity",
"tenantId": "599254d5-5f95-4f88-9bda-70ccd1dfe125",
"id": "5f9a1b6c-2dc7-4875-a5df-d6c3fb15399f"
}
}
},
"resultInfo": {
"@odata.type": "#microsoft.graph.resultInfo",
"code": 500,
"message": "Server Internal Error. DiagCode: 500#1203002.@",
"subcode": 1203002
},
"state": 8
}
}
]
}

Start with Samples/PublicSamples/PsiBot and reproduce the local meeting-join flow, then inspect the Deleted notification and its resultInfo code. Compare the setup and findings with issue #828. Done means identifying why the established call is deleted and documenting a verified fix or required configuration.