Portfolio for Jira is not filtering out user stories by assignment when grouping by team

[Denys Masko]

Hi, have an issue with a Porfolio for JIRA when trying to group the Scope by teams.

Here is my setup:

1. Created a new Porfolio plan that is using a project as data source.
2. Have setup several teams with members in Porfolio-Teams tab.
3. User stories in the project are assigned to different users that are Porfolio teams members.
4. When I"m at Scope tab of the Porfolio plan user stories ARE grouped by teams BUT some of them are distributed randomly - user stories assigned to Team A members are displayed under Team B.
5. In Porfolio configuration "Scheduling Options"-"Issue assignee import level" is "Story".  

Is it a kind of expected behavior?

Thanks in advance for any info on this issue.

[Denys Masko]

Also unassigned user stories are being distributed randomly between teams in Portfolio - Scope tab.