git-tf fails to connect to TFS server that is configured to force PKI certificate for authentication

Mar 22 at 12:19 PM
I have 2 TFS servers, "TFS1" is TFS 2013.4 in Domain1 that still uses userid & password, the other is "TFS2" as TFS 2015.1 in domain2 and requires PKI smartcard authentication. Additionally TFS1 is configured for HTTP on 8080, TFS2 is HTTPS of 443. I have no issues connecting to TFS1. On TFS2, I initially was getting the java security (certificate) error until I imported the TFS2 server certificate. After doing so, it says it is connecting to TFS server, but never prompts for any authentication and immediately states it "cannot find a valid TFS Collection at {collection URL}. I can connect to the collection through Visual Studio so I know the collection is valid. I am confident that the issue lies in the authentication (or lack of) with the TFS server from git-tf.

Any assistance or advise is greatly appreciated.