We are facing same issue with truesight installation. VM's are in workgroup. Have you got any solution for this..?
I had this same situation, i did two things to solve the issue:
1. I used Chrome.
2. In the hyperlink after I entered the credentials to authenticate in the SSO, I had to complete the redirected URL to the TSPS with the domain that I used.
I hope this works for you also.
Erik Paul GP.