Nelson rules

[#1]

I have made a control chart and activated all the 8 Nelson rules. I get a warning for rule #2, however, I cannot see why. Is there something in my underlying data set that could affect the script?

[#2]

Is it possible you have points hidden but not excluded?

[#3 · Accepted solution]

No, I have some data point hidden AND excluded. When I remove them the Nelson warning disappears. They are obviously not excluded from the Nelson rules, though.