Streaming API heartbeat issue

[bfexplorer]

Even when setting the heartbeat to 15 minutes:

{"op":"marketSubscription","id":3,"segmentationEna bled":true,"initialClk":"4BuJueTYIuIbrJnswiLjG7OY4 9ki","clk":"AOi3AgD7vAEA7/wB","heartbeatMs":900000,"conflateMs":500,"marketF ilter":{"marketIds":["1.158856875"]},"marketDataFilter":{"fields":["EX_MARKET_DEF","EX_LTP","EX_TRADED_VOL","EX_BEST_ OFFERS_DISP"],"ladderLevels":3}}

API posts response every couple seconds (3-5 seconds).