Problem with GridLayout Cell Height

I am seeing what seems like unusual behavior in the GridLayout, where the height of the cell varies depending on the content of the label inside it. See the attached screenshot.

The same code is creating a label as the component inside each cell, using the same style, which is:

  .i3rcontentval {
    font-size: small;
    margin: 2px 3px;
    overflow: auto;
    white-space: pre-wrap;
    word-wrap: break-word;

It seems to be as if the cell renderer sees the space, thinks it may cause a word wrap (though it won’t), and adds an extra row of height.

Note I can change the white-space to normal, and it works the way I expect it to. But then it will squeeze out any prepended spaces in the label text, should there be any.