Can't assign a lead to a user via API on creation

Hi all,

I'm looking for a little help with the SugarCRM API.

I'm trying to create a lead, using the API, and would like to assign that lead to a specific user.

This is the data I'm currently passing:

first_name: "TEST",
last_name: "TEST",
email: [
assigned_user_id: 'some active user id'

This is the endpoint I'm hitting:


From what I've read elsewhere on the forum, adding the assigned_user_id field should be sufficient to assign the lead to the specified user, however it seems to randomly assign them to another user.

Is there anything else I need to check?

Any advice appreciated.