SYMPTOM:
Database Connection monitor in Strategy Developer 9.4.x-10.x, displays connections made to Database Based History List repository as "Repository Connections" with no data in Database Connection and Database Login columns as seen below:

As seen in the Database Connection Management trace below Connection ID: 2 is created for History List Repository stored in Informix and thus should be displayed as such in the Database Connection monitor as well.
Connection ID: 1 is created for the Enterprise Manager Warehouse and Connection ID: 3 is created for Tutorial Warehouse. These two connections are correctly displayed in the Database Connection monitor in Strategy Developer.
Connection ID: 0 and Connection ID: 4 are both created for the metadata and should be the only ones displayed as "Repository Connections".
Connection created: Connection ID: 0, Connection String: DSN=Strategy_Tutorial_Metadata;, Multiprocess, Non-extended Fetch, Row by Row Insertion, Synchronous Connection created: Connection ID: 1, Connection String: DSN=EM WH SQL Server;UID=NJA0JAN22U4;, Multiprocess, Non-extended Fetch, Row by Row Insertion, Synchronous Connection created: Connection ID: 2, Connection String: DSN=IBM Informix_HL;UID=test_user;, Multiprocess, Non-extended Fetch, Row by Row Insertion, Synchronous Connection created: Connection ID: 3, Connection String: DSN=SQL Server Tutorial Warehouse;UID=em_user;, Multiprocess, Non-extended Fetch, Row by Row Insertion, Synchronous Connection created: Connection ID: 4, Connection String: DSN=Strategy_Tutorial_Metadata;, Multiprocess, Non-extended Fetch, Row by Row Insertion, Synchronous