Signal table in kafka connector

I tried using Debezium (1.6) signal table to take snapshot for newly added tables in SQL Server connector. When I inserted a signal of event type execute-snapshot, it took a snapshot initially. When I sent the signal the second time, it stopped taking the snapshot and started inserting snapshot-window-open and close events into the signal table. It is inserting the records continuously without stopping, which results in high disk usage. Can someone please help me with this.