a problem on stop loss

 

i have set a stop lose but he never go there and stop anyway why?

please see the image


Chart GBPCHF, M15, 2018.11.23 20:50 UTC, MetaQuotes Software Corp., MetaTrader 5, Demo
 

You sell the Bid price and buy the Ask. The chart shows ONLY Bid prices. So your SL of 1.27854 was hit by the Ask price which is not painted on the chart and which is above the Bid.

So everything is as it should be.