Filter for one label removes every item

[Marc Lefebvre]

I'm trying to filter out issues I've labelled with the word 'Outlier' from the Control Chart. Whenever I apply that filter it removes every issue, even ones that do not have that label. Why is this not working? The filter syntax I'm using is:

labels != Outlier

I've also tried:

labels not in (Outlier)

Thanks.

[Vasiliy Zverev]

It seems that issues with no label are also removed. Try this: and (labels != Outlier or labels is empty)