DrawHorizontalLine breaks optimization

Hello, I'd like to ask if there is any chance to keep drawing on chart even in optimization. I have this line:

Chart.DrawHorizontalLine("label", level, Color.Aqua, 1);

Which I use in backtesting to help me visualize levels where trades were open. But if I keep this line (not comment it out) and start optimization, I get a random number of empty results. All of the values are 0 for all results. As soon as I comment this out, I get normal results. It's a bit frustrating to always comment it out before optimization. Is there a way to write this so that I don't have to do this?

Thanks.