We have a tiered project system in which issues are moved into different projects as they are escalated. We are using Jira 5.2.11 currently, but since we converted direclty from 4.3.3 to 5.2.7, we have been experiencing inconsistent issues on the assignee when moving an issue. All our projects are set up to default to "Unassigned", however when we move an issue to another project, we are not offered the "Unassigned" option, but sometimes just a "-1" .
Another issue, that I cannot tell if it is related is that sometimes when a person moves an issue their name will stay as the assignee (even though the rule is to default back to unassigned in the new project). This is especially confusing as they do not have permission to be an assignable user in the new project! The most recent case of this did not show up in a filter after the assignee was reassigned to default, even though the ticket met all critieria (just project, unassigned, and not closed).
The logs are not indicating any issues when specifically searching for the task id in question.
Any ideas?