I've created a relatively simple trailing stop loss exit strategy which sets a trailing 10% stop loss. When backtesting this strategy against MSFT over the 2020 time period, I am hitting a puzzling issue. 

The stop order gets correctly updated with the trailing stop price during the 1/1-2/13 time period where MSFT is increasing from 160 to 188. The stop loss is set to 169. Then on 2/14, the stock price moves to 183. However, the stop loss executes! I've tried debugging this multiple ways, but am unable to get an idea.

I tried plotting the OHLC data for MSFT, and that shows that the price doesn't drop to 169 at all during 2/14. 

I've attached my code and backtest here. Would appreciate ideas.