My Indicator triggering when it shouldn't.

[trapperl]

I'm trying to learn how to make indicators and thought that I'd start simple, with DPO, and made an EA that only trades when the DPO crosses above zero and closes the trade when DPO crosses below zero.

The problem I'm having is that sometimes it will trade without the DPO line crossing zero.

I'm not sure what I'm doing wrong. I created the indicator from the code taken from MT5 but I think I'm missing something.

Does anyone have any advice?