@Shanuka Thushara Thank you for posting your question!
I understand your concern about the replication health status for your virtual machines has become critical and the infrastructure is showing as not connected. You have mentioned that all the pre-requisites are met.
I would suggest you check the following:
Check the replication settings for your virtual machines and ensure that they are configured correctly.
Check the connectivity between the source and target environments. Ensure that the necessary ports are open and that there are no network issues that could be preventing replication.
See if there are any replication related logs that could help you with more details about the error/issue you encountered. You can find these logs in the Azure Migrate project.
If none of this helps, then the best option would be contact Azure technical support team by raising a support ticket. The ticket enables you to work closely with the support engineers and get a quick resolution to your issue.
Here is the link - https://docs.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request to create support case.