There is a character limitation of the password field for Snowflake connection profiles in TDM Portal. We are unable to connect to Snowflake data sources, because of this limitation, as seen below.
TDM Portal 4.11
This has been addressed in the latest TDM Portal release - TDMWeb-4.11.4003.0. Please upgrade to the latest release of TDM Portal. The TDM patches are available for download at "Test Data Manager (TDM) Support Patches".