We are always working hard towards improving our indicators. This means we may sometimes add experimental features that we think might be nice to have. By doing so our users can opt-in to these new features and play around with them. It helps us because we can gather feedback from this.
For signal invalidations to work as designed it is dependant on two other settings:
Signal Style needs to be set to Only start of trend.
Adaptive Fractals need to be enabled.
When enabled, red crosses appear on several candles on the chart. This little red cross indicates that the candle it appears on invalidates the signal preceding it. In the sample below we see that a red candle invalidates the green signal before it and a green candle invalidates the red signal before it. We also see a red signal (on the right hand side of the chart) being invalidated by a white candle. This is due to the white candle wicking above the high of the red signal candle, thus invalidating the short signal.