SQL direct DB connection error

For a DR test to validate backups, I had a SQL admin restore the ChangeAuditor DB from the most recent backup to a DB with another name (ex. CAADrestore) on the same SQL server as the production database. I verified permissions and could browse tables, run queries, etc. using SQL Mgmt Studio. However, using the ChangeAuditor client, when I create a Database Direct manual connection profile with all the expected parameters (Test passes) and attempt to connect, it hangs for approximately 30 mins and throws a popup "The communication object. System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the faulted state.".  I only have Show Stack Trace and Exit Application as options. The Show Stack Trace text is very generic - 4Kb. I can post it necessary.

I tried connections with FQDN of the server and NetBIOS name, Credential = No and Yes but same results.

We have done this successfully before (a year ago) as part of our procedures. The User Guide doesn't really have any troubleshooting information and I'm not sure what logs to look at to see what/where the issue may be. Perhaps, it's some .NET incompatibility because we're running an older version - 6.5? Any suggestions on how to troubleshoot this?