Hi Krzysztof,
my guess is that the formula of that calculated field calculates the number of working days between an issue field value (e.g. Created) and now, or another moment of time that is _not_ dependent on just fields of the issue. The problem is that the index entry for an issue is only updated when the issue is modified (edited) or transitioned. Not when time passes (that would mean constantly re-indexing, which is impossible).
As an example, if you're calculating the number of days _since_ issue creation, the value will change between one day and the next, without making any change to the issue itself. Therefore, the index will become obsolete for that issue as time passes.
As for your question: "Is there a way to force Jira to auto re-index when that custom field value is changed?"
The thing is, the calculated field's value only changes... when it is computed. So what you'd want is to force the field to be recalculated constantly - which is equivalent to rebuilding the index for every issue all the time. No doable.
So, no, you cannot use calculated fields whose value is time-dependent in JQL searches.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.