The client application 1 inserts from the DB2 database and creates a lock IX to the lock X table on the line.
Client applications 2 and 3 attached to the same database attempt to make selects to the same table and the application blocks. In the database shows information that applications 2 and 3 have an IS lock on the line.
When you exit the client application 1, client applications 2 and 3 are unlocked, but the inserts sent to the database are not in the table. There is no TCP / IP error in log files.
It seems that the application disconnects before being committed.