Create Automation Task: required 'assignee' field even if it is filled

Hi,

I'm trying to create a 'Automation Task', but I'm always receiving this error message.

Problem:

A test automation task can not be created, because the mandatory field 'Assignee' (it is shown twice) can not be filled.

We're using Jira v8.14.1.

Thanks,

Nikolai Steinebrunner