If set try to persist the state of expanded rows. You need to specify primaryKey on the initialization of the grid in order to enable this feature.
Examples
True
<div class="container">
<div class="row">
<div class="col-xs-12">
<p>Expand row, then change the page and return back to the page with expanded row in order to see that the expansion is kept.</p>
<table id="grid"></table>
</div>
</div>
</div>
<script>
var grid = $('#grid').grid({
uiLibrary: 'bootstrap',
primaryKey: 'ID',
dataSource: '/Players/Get',
columns: [ { field: 'ID', width: 34 }, { field: 'Name' } ],
detailTemplate: '<div><b>Place Of Birth:</b> {PlaceOfBirth}</div>',
keepExpandedRows: true,
pager: { limit: 2, sizes: [2, 5, 10, 20] }
});
</script>