How does JIRA Portfolio determine what Team to auto assign a ticket.

[Jeff]

Each team is tied to a scrum board in JIRA portfolio - How does JIRA Portfolio determine what Team to auto assign a ticket to?

I cant seem to figure out a theme. The result is some tickets are blank and others are other assigned correctly.

[Juliano_de_Lemos]

I guess I face the same issue. I've created a plan and included some boards to it, then Portfolio: 

• imported the issues and linked to the releases matching with the "fix version" set in each issue 
• automatically created the teams matching with the boards 
• but didn't assigned the issues to the teams
  My expectation is that Portfolio would do so by matching the team with the board (filter) where the issue appears... But it didn't happen.
  
  I am missing something?