fix(volumeLoad): should not have missing slices when loading (#3287)

* fix(volumeLoad): should not have missing slices when loading

* add review comments

extensions/cornerstone/src/services/ViewportService/CornerstoneViewportService.ts

@@ -506,19 +506,16 @@ class CornerstoneViewportService extends PubSubService
       !hangingProtocolService.customImageLoadPerformed
     ) {
       // delegate the volume loading to the hanging protocol service if it has a custom image load strategy
-      if (
-        hangingProtocolService.runImageLoadStrategy({
-          viewportId: viewport.id,
-          volumeInputArray,
-        })
-      ) {
-        // Fallback to the default strategy if the custom one fails
-        return;
-      }
+      return hangingProtocolService.runImageLoadStrategy({
+        viewportId: viewport.id,
+        volumeInputArray,
+      });
     }
 
     volumeToLoad.forEach(volume => {
-      volume.load();
+      if (!volume.loadStatus.loaded && !volume.loadStatus.loading) {
+        volume.load();
+      }
     });
 
     // This returns the async continuation only