Jira multi-user picker does not seem to recognize comma as a delimiter

Issue Summary

When a Fullname contains comma as delimiter while adding user details in multiuser picker field the username is not recognized and throws error as " could not find username"

Steps to Reproduce

1. create a multi-user picker field
2. create a user with full-name as lastname,firstname
3. Now create an issue and select the above user in the multiuser picker field
4. on submitting the ticket we see an error as "could not find username"

Expected Results

User name should accepted and ticket should get created successfully

Actual Results

Ticket failed to get created with error as " could not find username"

Workaround

Escape the comma in the user picker field (e.g., "John\, Doe"), or create full names without using comma as delimiter.