[v11.0.x] XYChart2: Fix tooltip mode (#87151)

public/app/plugins/panel/xychart/v2/XYChartPanel.tsx

@@ -38,7 +38,7 @@ export const XYChartPanel2 = (props: Props2) => {
   let { builder, prepData } = useMemo(
     () => prepConfig(series, config.theme2),
     // eslint-disable-next-line react-hooks/exhaustive-deps
-    [mapping, mappedSeries, props.data.structureRev, props.fieldConfig]
+    [mapping, mappedSeries, props.data.structureRev, props.fieldConfig, props.options.tooltip]
   );
 
   // generate data struct for uPlot mode: 2

public/app/plugins/panel/xychart/v2/XYChartTooltip.tsx

@@ -24,7 +24,7 @@ export interface Props {
 }
 
 function stripSeriesName(fieldName: string, seriesName: string) {
-  if (fieldName.includes(' ')) {
+  if (fieldName !== seriesName && fieldName.includes(' ')) {
     fieldName = fieldName.replace(seriesName, '').trim();
   }