Reverted changes. Not sure why the same method works on date-picker but not here.

assets/src/scripts/monitoring-location/components/hydrograph/vue-components/method-picker.vue

@@ -6,6 +6,7 @@
     >
       Sampling Methods/Sub-locations:
       <span
+        class="usa-tooltip"
         ref="tooltip"
         data-position="right"
         title="The names used in dropdown menu are often specific to a particular monitoring location and describe sampling details used to distinguish time-series of the same type--examples include variations in physical location and sensor type."
@@ -70,18 +71,13 @@ export default {
       return props.sortedIvMethods.methods.findIndex(method => method.pointCount === 0) > -1;
     });
 
-    const initializeUSWDSTooltip = function() {
-      tooltip.value.setAttribute('class', 'usa-tooltip');
-      uswdsTooltip.on(tooltip.value);
-    };
-
     onMounted(() => {
       if (document.readyState === 'complete') {
-        initializeUSWDSTooltip();
+        uswdsTooltip.on(tooltip.value);
       } else {
         document.addEventListener('readystatechange', (event) => {
           if (event.target.readyState === 'complete') {
-            initializeUSWDSTooltip();
+            uswdsTooltip.on(tooltip.value);
           }
         });
       }