Querying an Oracle view don't return records using some clients but it does using others
The TNS Listener running on the server hosting the database has a log file located (on Unix-type servers using Oracle recommended naming) at 

/u01/app/oracle/diag/tnslsnr/$HOSTNAME/listener/trace/listener.log


The file listener.log may be named something else if you have multiple listeners.  That log file will show the connection parameters presented by users connecting to the database via the TNS Listener.  I would compare the information in the log for the two connections to see the differences.  And if that looks the same, Michael Kutz' comments would be accurate; there may be a login trigger that looks at the program connecting; if you look at the table  v$session you can see the program column might be used to restrict access.