Replying to third-party platform using Teams using Microsoft Graph after completed migration

Question

I have created team and imported messaged in Migration mode as instructed in Here using Microsoft Graph. After completing the migration and started with the teams, I am not able to reply to earlier messages. any new messages can be replied. On exploring the API request by Teams web client I noticed that it fails to locate the resource for POST method. Error in Console: MessageService: actionHandlerSendMessage: Error while sending message 5056292646843901000 executed by OAM: {"statusCode":404,"headers":{"cache-control":"no-store, must-revalidate, no-cache","content-length":"184","content-type":"application/json; charset=utf-8","contextid":"tcid=0,server=msgapi-production-ejp-azsc2-1-90,cv=RbaShQdVLUq+aYgnLEBmcg.0","pragma":"no-cache"},"errorMessage":"{\r\n "subCode": "PostNotFound",\r\n "details": "Post does not exist in the thread.",\r\n "errorCode": null,\r\n "errorSubCode": null\r\n}","errorCode":404,"request":{},"conversationId":"19:e5f57773b5f84f62ba773362cadf1ac6@thread.tacv2"}