Adaptive Server 15.7 and later changes the way cursors support transactions:
Adaptive Server:
- Does not automatically close an open cursor declared with a for update clause if you commit a transaction. To close a read-only cursor when a transaction is committed, set the close on end tran option
- Supports fetch operations on open cursors after the transaction has been committed
See the Reference Manual: Commands and "Cursors: Accessing Data" in the Transact-SQL Users Guide.