Issues with ZigZag Indicator of MT4

 

I use the built-in ZigZag indicatior of MT4 with settings shown in the image attached.

Although 'depth' is set to 4, but the indicator draws two minima with only one bar in between. Isn't it a bug?

I thought if depth is set to 4, the indicator should draw a minimum with at least 4 candles between two minima.

Any thought on this issue?

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