Here is the code in RefreshRange. It shows what has to be done to get the currentcell refreshed.
public void RefreshRange(GridRangeInfo range, GridRangeOptions options, bool forceRefreshCurrentCell)
{
TraceUtil.TraceCurrentMethodInfoIf(Switches.BeginEndUpdate.TraceVerbose, PaneDesc, range);
if (this.ShouldPrepareUpdate(true))
{
Model.ResetVolatileData();
InternalInvalidate(RangeInfoToRectangle(range));
if (forceRefreshCurrentCell && range.Contains(CurrentCell.RangeInfo))
CurrentCell.Refresh();
Update();
}
}