Can someone pls explain this trade to me?

Hello. I would to ask a question in regards to a trade. So, I took a short trade on GBP/USD on 1.59897 and put my stop at 1.60108. My stop loss was triggered at 11/4 at 5.30 and the sale covered at 1.60111. The problem is that, according to my MT4 and other charting software that I use, the price never reached nor the stop nor the price at which it was covered. The high for that time was 1.60082.

I know that a stop loss is triggered when the price reaches bid/ask, so lets say the spread triggered the S/L...my question how can my cover price be "out of chart"? I am using an Oanda demo at the moment. Thanks for the reply.