JDBC: ERROR: portal "C_2" does not exist

Greetings,

When I do a resultSet.next(), I am getting an exception:  ERROR:
portal "C_2" does not exist

The facts:

64-bit Linux
JDK 1.8.0_322
postgresql-42.3.3.jar
psql (PostgreSQL) 14.2

conn.setAutoCommit(false);

PreparedStatement pstat = conn.prepareStatement(sql);

pstat.setFetchSize(50);

I do a query that will have thousands of records.  I get the first 50
just fine.  When I do:

rset.next() the 51st time, I get an exception:  ERROR: portal "C_2"
does not exist

There is no C_2 anywhere in my code or query.

Sure appreciate any help!

Thanks!

Blake McBride