Bug: One character in dialog field label causes wrong redrawing

Working on my previous project to change batch caption dialog field, I found a strange bug when it came to redrawing dialog window.

If we place any dialog field below a combobox with a label even of one character longer than the latter, AX fails to redraw the window entirely after modifying combobox value and changing Main instruction text.

protected Object dialog()
{
    FormComboBoxControl  combobox;
    dlg                 = super();

    dialogEventType = dlg.addFieldValue(EnumStr(uapInterfaceEventType), eventType, '1234567890' );
    dialogAnother   = dlg.addFieldValue(identifierStr(VendName), vendName, '12345678901');
    // to add details to the caption and task description in batch tasks
    dialogEventType.registerOverrideMethod(methodstr(FormStringControl, modified), methodstr(tmxRunBaseBatchSample, eventType_modified), this);
    // to avoid user input in the field
    combobox = dialogEventType.control();
    combobox.comboType(1);

    return dlg;
}