I have a working integration setup between JSM (both PROD and Sandbox) and Microsoft Teams. Currently, all alerts go to one Teams Channel.
Recently, I wanted to categorize this and forward alerts to different Channels based on their type. The issue is, I am unable to choose a Team when I try to configure the integration. It doesn't display any Team that are available in MS Teams. I am sure it used to display them earlier. Screenshot attached to show the issue. 
The Enterprise App named 'Atlassian-ChatOps' in Azure has required permissions with Admin consent such as
- Team.ReadBasic.All
- Channel.ReadBasic.All
along with few more. And the existing integrations working is a sign that necessary permissions have been configured.
The tenant itself has been connected for both PROD and Sandbox for years. Screenshot attached. 
To make things worst, I did a reset of the current integration in SBX and now I have the same problem with it.
Summary: Tenant is connected, permissions configured for Enterprise App in Azure, already a working solution, but unable to reconfigure it nor add a new integration.
Any suggestions will be helpful.