To properly synchronize Assignee fields, we need to manually identify which user is representing the same person. E.g. we can have John Doe being named John in Jira and johnd in GitLab. Thus that getint.io is not able to automatically interpret, that this is the same person, especially that when fetching users, each app operates on different IDs. E.g. Jira Cloud uses some accountId hash while Jira Server uses username as id.
To manually identify and correlate users in both apps:
Go to Fields Mappings and click cog icon to get into mapping details
2. Select from dropdowns in Map available options, options that representing the same user
3. Click Add button
4. You should see the correlated users representing the same
5. Click DONE button to save Type Mapping changed configuration. SAVE integration to persist your changes.