Ran into an issue where I was getting the following error message.
Looking at this post -> "InvalidOperationException: IDX20803: Unable to obtain configuration from: '[PII is hidden]'"
I was able to correct this issue with - ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12
Not sure if this was an update on Azure or the Identity provider on Azure, but I am just trying to look into this to see if I can find a root cause.