Hi Steve,
Do you know if any new custom fields have been added or modified since the cube was initially imported?
Something you may want to try is emptying the cube and re-importing all of the data. This is different than a simple re-import as it will re-import all the dimension members as well. I had a similar issue before I realized that I had changed the name of a Board in Jira. Empty and re-import did the trick!
In eazyBI, changes of issue Priority are also imported. It means that, depending on the measure you are using in the report, you see either historical situation (bugs are included by their historical priority) or by the current priority. If you use any of the historical measures, issues would be counted by the priority at the transaction moment or at the end of the selected time period: https://docs.eazybi.com/eazybijira/data-import/jira-issues-import/import-issue-change-history
You may want to check what measures are used in the report (also in calculated measures). To ensure that all issues are counted by the current priority, you may use Issues created measure (it depends on the report’s overall structure and calculations).