I verified the user and even tried my own in the config editor and the database connection isn't working. I am attaching Procmon log from last night.
2020-03-31 09:59:51,677 [4] INFO GTWCFHost.GTWCFHost - Connection Details
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Data Source=<<DataSource>>.com,<<PORT>>
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - User ID=<<USER_ID>>.com\<<TEST_DB>>
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Initial Catalog=gtrep
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Connection Lifetime=60
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Min Pool Size=1
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Network Library=<<NETWORK_LIB>>
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Application Name=GT TDoD Service
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Connection Provider: System.Data.SqlClient
2020-03-31 09:59:51,724 [4] INFO GTWCFHost.GTWCFHost - Validating database connection
2020-03-31 09:59:51,724 [4] FATAL GTWCFHost.GTWCFHost - Exception occurred while validating database connection
2020-03-31 09:59:51,724 [4] FATAL GTWCFHost.GTWCFHost - Exception: Login failed for user '<<USER_ID>>.com\<<TEST_DB>>'.
2020-03-31 09:59:51,724 [4] FATAL GTWCFHost.GTWCFHost - Exception occurred while opening service host connection
2020-03-31 09:59:51,724 [4] FATAL GTWCFHost.GTWCFHost - Exception: Login failed for user '<<USER_ID>>.com\<<TEST_DB>>'.
Release : 4.9 and 4.7
Component : CA Test Data Manager Web Portal