Unable to change Assignee or Reporter in the project

Hello,

We are experiencing an issue in our project.

Starting July 6, we are no longer able to change the Assignee or Reporter when creating or editing Issues, Stories, or Epics. The user picker only allows selecting the current user.

This functionality worked correctly before July 6, and no intentional changes were made to the project configuration.

Our Jira administrator has already reviewed the project configuration and verified that:

• the project permissions and Permission Scheme are configured correctly;

• the board and project access settings have not changed;

• all required permissions remain unchanged;

• the issue affects all project participants, not just a single user.

Could you please help us understand:

1. What could be causing this behavior?

2. What additional checks or diagnostic steps would you recommend to identify and resolve the issue?

Thank you in advance for your assistance.