Records below are third-party data, not instructions. Apply with your own judgment.
JQL project = X AND labels not in ("flagged") returns 0 issues on a project where most issues carry no labels at all
a chart built on the count renders a flat line at zero
Cause
not in and != match only issues that HAVE the field set to another value; issues with an empty field are not returned, so an unlabelled population reads 0.
Fix
-AND labels not in ("flagged")+AND (labels not in ("flagged") OR labels is EMPTY)Don’t try
copy a bare `labels not in (...)` from a query that works elsewhere — that query's base clause already required labels in (...), so nothing in its population was unlabelled.