Depending on the version of the ORB, there is a case where the license of the Client for ODBC won't be detected when creating the redundant pair.
Therefore when trying to connect to the ORB redundant pair, the ODBC client will keeping switching from Primary to Stand By but never connect.
If you take a look at the log file for the redundant pair created, you will see who the license is not detected.
This needs to be solved manually.
You must take the code inside ODBC Client license file and copy it into the ORB license file, at the bottom of the file.
Then reboot the service, it should work.