Issue Summary

When using "WAS" operator with a predicate pointing to a time frame before field of interest was first modified, no results are returned.

Documentation has an imprecise statmenet on it:

 This operator will match the value name (e.g. "Resolved"), which was configured in your system at the time that the field was changed.

Steps to Reproduce

1. Create an issue.
2. Next day (or more), change issue resolution to "Resolved" and back to "None". 
3. Issue two searches with JQL as below, but:
   1. First JQL with a date the day SAME or LATER as creation date, but EARLIER the first change of "resolved" field.
   2. Second JQL with a date AFTER the change from "Resolved" to "None"

resolution was EMPTY ON "2020-02-04"

Expected Results

Both JQL queries should be returning created issue.

Actual Results

1. First JQL: created issue is not on the list
2. Second JQL: created issue is on the list

Workaround

Initial "Resolved" field value can be changed for future WAS searches to work

CHANGED operator can cover some of the cases, e.g.:

resolution changed from empty after "2020-02-04"