diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/ControllerManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/ControllerManager.java
index 44aa430ec2..d92c58b366 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/ControllerManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/ControllerManager.java
@@ -8,6 +8,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import io.javaoperatorsdk.operator.api.config.ExecutorServiceManager;
 import io.javaoperatorsdk.operator.processing.Controller;
 
 /**
@@ -32,20 +33,27 @@ public synchronized void shouldStart() {
   }
 
   public synchronized void start(boolean startEventProcessor) {
-    controllers().parallelStream().forEach(c -> c.start(startEventProcessor));
+    ExecutorServiceManager.executeAndWaitForAllToComplete(controllers().stream(), c -> {
+      c.start(startEventProcessor);
+      return null;
+    }, c -> "Controller Starter for: " + c.getConfiguration().getName());
     started = true;
   }
 
   public synchronized void stop() {
-    controllers().parallelStream().forEach(closeable -> {
-      log.debug("closing {}", closeable);
-      closeable.stop();
-    });
+    ExecutorServiceManager.executeAndWaitForAllToComplete(controllers().stream(), c -> {
+      log.debug("closing {}", c);
+      c.stop();
+      return null;
+    }, c -> "Controller Stopper for: " + c.getConfiguration().getName());
     started = false;
   }
 
   public synchronized void startEventProcessing() {
-    controllers().parallelStream().forEach(Controller::startEventProcessing);
+    ExecutorServiceManager.executeAndWaitForAllToComplete(controllers().stream(), c -> {
+      c.startEventProcessing();
+      return null;
+    }, c -> "Event processor starter for: " + c.getConfiguration().getName());
   }
 
   @SuppressWarnings({"unchecked", "rawtypes"})
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ExecutorServiceManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ExecutorServiceManager.java
index 5dcba5975d..06eda871f2 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ExecutorServiceManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ExecutorServiceManager.java
@@ -72,7 +72,7 @@ public static <T> void executeAndWaitForAllToComplete(Stream<T> stream,
         Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()));
 
     try {
-      instrumented.invokeAll(stream.parallel().map(item -> (Callable<Void>) () -> {
+      instrumented.invokeAll(stream.map(item -> (Callable<Void>) () -> {
         // change thread name for easier debugging
         final var thread = Thread.currentThread();
         final var name = thread.getName();
@@ -91,11 +91,13 @@ public static <T> void executeAndWaitForAllToComplete(Stream<T> stream,
         } catch (ExecutionException e) {
           throw new OperatorException(e.getCause());
         } catch (InterruptedException e) {
+          log.warn("Interrupted.", e);
           Thread.currentThread().interrupt();
         }
       });
       shutdown(instrumented);
     } catch (InterruptedException e) {
+      log.warn("Interrupted.", e);
       Thread.currentThread().interrupt();
     }
   }
diff --git a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java
index 6d161aca9e..d8b2312ebb 100644
--- a/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java
+++ b/operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/event/EventSourceManager.java
@@ -86,6 +86,10 @@ private static Function<NamedEventSource, String> getThreadNamer(String stage) {
     };
   }
 
+  private static Function<NamespaceChangeable, String> getEventSourceThreadNamer(String stage) {
+    return es -> stage + " -> " + es;
+  }
+
   @Override
   public synchronized void stop() {
     stopEventSource(eventSources.namedControllerResourceEventSource());
@@ -179,13 +183,15 @@ public void broadcastOnResourceEvent(ResourceAction action, P resource, P oldRes
   public void changeNamespaces(Set<String> namespaces) {
     eventSources.controllerResourceEventSource()
         .changeNamespaces(namespaces);
-    eventSources
+    ExecutorServiceManager.executeAndWaitForAllToComplete(eventSources
         .additionalEventSources()
         .filter(NamespaceChangeable.class::isInstance)
         .map(NamespaceChangeable.class::cast)
-        .filter(NamespaceChangeable::allowsNamespaceChanges)
-        .parallel()
-        .forEach(ies -> ies.changeNamespaces(namespaces));
+        .filter(NamespaceChangeable::allowsNamespaceChanges), e -> {
+          e.changeNamespaces(namespaces);
+          return null;
+        },
+        getEventSourceThreadNamer("changeNamespace"));
   }
 
   public Set<EventSource> getRegisteredEventSources() {
diff --git a/operator-framework/src/test/java/io/javaoperatorsdk/operator/MultiVersionCRDIT.java b/operator-framework/src/test/java/io/javaoperatorsdk/operator/MultiVersionCRDIT.java
index 2126f129c7..d00fc48489 100644
--- a/operator-framework/src/test/java/io/javaoperatorsdk/operator/MultiVersionCRDIT.java
+++ b/operator-framework/src/test/java/io/javaoperatorsdk/operator/MultiVersionCRDIT.java
@@ -132,7 +132,7 @@ void invalidEventsShouldStopInformerAndCallInformerStoppedHandler() {
     operator.create(v1res);
 
     await()
-        .atMost(Duration.ofSeconds(1))
+        .atMost(Duration.ofSeconds(2))
         .pollInterval(Duration.ofMillis(50))
         .untilAsserted(() -> {
           // v1 is the stored version so trying to create a v2 version should fail because we cannot