During the quant course it came up, and I have come across it a few times, where a long trade has supposedly lost well over 100%, sometimes well above 1000%.
The profit analysis and trade list both show the massive loss. But measuring the indicators on the chart shows a reasonable loss.
Interestingly, if you trim those losses with the sliders on the profit analysis graph, the backtest profit decreases. So not sure what is going on there.
Did you ever get to the bottom of this issue?