Mysterious problem with Database Toolbox COLUMNS and %PRIVILEGES functions

I have used the COLUMNS function in the Database Toolbox for several years without a problem in connection with our firm's Microsoft SQL DB. Using com.microsoft.sqlserver.jdbc.SQLServerConnection 4.1. Sometime last month, the function began returning an empty set (Class 'double'). To test if this was a permission issue, my permissions were elevated to Sys Admin level. This did not solve the problem. In addition, the COLUMNPRIVILEGES function also returns an empty set. TABLEPRIVILEGES returns correct permissions at the Sys Admin level but none otherwise, but I actually have them even with limited permissions. We have tried replacing the JDBC connection with ODBC and that has not fixed the problem. We have also migrated backwards to jdbc.SQLServerConnection 4.0 and to 2014b under which it previously worked flawlessly and still the problem persists. Matlab's code has not changed since 2012. I am told by our DB group that my permissions have not changed. It has previously worked under all combinations of R2014a, R2014b, R2015a and 4.0 and 4.1 but no longer.

Has anyone else experienced this problem or have any clue how to analyze it? Thanks.