12.1p+: ListGrid groupSummary with showGroupSummaryInHeader plus summaryRow bug

[Blama]

Hi Isomorphic,

retesting this issue in this modified sample (v12.1p_2023-06-27, also v13.0p_2023-07-12) I noticed that showGroupSummaryInHeader is broken if used in combination with summaryRow.
The groupSummary is plain white (unexpected) and only shows correctly after clicking it.

isc.ListGrid.create({
    ID: "dsListGrid",
    width: "100%",
    height: "100%",
    dataSource: "supplyItem",
    autoFetchData: true,

    // GroupSummary not OK
    groupByField: "category",
    groupByMaxRecords: 10000,
    showGroupSummary: true,
    // This does not work as expected
    showGroupSummaryInHeader: true,

    // GridSummary is OK
    showGridSummary: true,
    summaryRowDataSource: "supplyItem",
    summaryRowCriteria: {"SKU": 45300}
});

Best regards
Blama