Helpdesk module: Related Partner field changes user_id name and Related Partner

Summary

When you assign Created By field and choose a user, after that changing Related Partner field changes also Created By field

Steps to reproduce

Create ticket. Choose 'admin' in Created By. Change Related Partner to 'Agrolait, Edward Foster'.

What is the current bug behavior?

Created By field has changed to 'Edward Foster'. The admin user is now related to 'Agrolait, Edward Foster' (see user admin settings)

What is the expected correct behavior?

Do not change Created By field when assigning Related Partner

Relevant logs and/or screenshots