Place the following JavaScript function on the page where the grid is located. This will override an internal function where the Sort expressions are built and change it to use the DataField instead of Column UniqueName.
<script type="text/javascript">
Telerik.Web.UI.GridMobileColumnView.prototype._click = function (e) {
var $target = $(e.target);
var owner = this.get_owner();
var uniqueName = this._column.get_uniqueName();
var dataField = this._column.get_dataField(); // DataField to be used instead of Column UniqueName
var view;
if ($target.hasClass("rgFilter")) {
view = owner._getViewByType(Grid.MobileViewType.Filter);
} else if ($target.hasClass("rgColumns")) {
view = owner._getViewByType(Grid.MobileViewType.Columns);
} else if ($target.hasClass("rgButtonSortAsc")) {
this._handleSort(dataField + " ASC");
} else if ($target.hasClass("rgButtonSortDesc")) {
this._handleSort(dataField + " DESC");
} else if ($target.hasClass("rgButtonSortClear")) {
this._handleSort(dataField + " NONE");
} else if ($target.hasClass("rgFreeze")) {
this._column._toggleFreeze();
this.close();
} else if ($target.is(this._$groupOption)) {
if (this._$groupOption.prop("checked")) {
owner.fireCommand("UnGroupByColumn", uniqueName);
} else {
var isClientDataSourceBinding = !!owner._owner._clientDataSourceID;
owner.fireCommand("GroupByColumn", isClientDataSourceBinding ? dataField : uniqueName);
}
}
if (view) {
view.show(this._column);
e.preventDefault();
}
}
</script>