There seems to be a problem when there is an activity running in the background and when the statusbar is higher than usual (like when you have an active call):

Loading screen (with active call):

Loading screen (without active call):

Simple grid layout (with active call):

Simple grid layout (without active call):

Here is the XML for the grid layout page:

<Page xmlns="http://www.nativescript.org/tns.xsd">
  <Page.actionBar>
    <ActionBar title="TEST"/>
  </Page.actionBar>

  <GridLayout rows="auto, *, 30">
    <Label row="0" text="TOP" fontSize="20"/>
    <ListView row="1"></ListView>
    <Label row="2" text="BOTTOM" fontSize="20"/>
  </GridLayout>
</Page>