Less mixin formatting issue

Hi,

Usually I use the autoformat of the code with Webstorm and there were any problems.

No I have the LESS mixin:

select:not([multiple]){
    .media(@tablet; { 
        .........................
    });
}

and it reformats to one line during reformating:

select:not([multiple]){
    .media(@tablet; { border: 1px solid @mobile-forms__border; });
}

How I can keep the initial formatting with line brake after each brace?