Wrong root after IntelliJ loaded the second sbt module Follow

Project structure:

root

--  src

    -- ...

--  build.sbt

--  test

    --  ui-test

        --  src

             -- ...

        --  build.sbt

After I loaded the project from root, I added a module from ui-test manually from project structure and succeeded. But I could not open project structure window again and crashed after several tries. Also if I reopen IntelliJ with the project, the root project is gone and the content root will be ui-test instead of root.

I tried to reset and reload several times and got the same results.

Please have a look on this issue.

Thanks.