Market trigger limit-order pre short-selling

hi,

Today i traded short sell on [email protected](market sell) for 1000 quantity and placed a SL-M order at 314.9 price to buy(. to have max loss of 1500) but as the market was on Bull phase …it went to 320.5 but to my surprise the trigger price didn’t executed and it made me around 7K loss today. Can u please explain me why it is happened.