diff --git a/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeGrpcSession.java b/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeGrpcSession.java
index 74edc66084..7fa5cc399e 100644
--- a/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeGrpcSession.java
+++ b/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeGrpcSession.java
@@ -92,7 +92,6 @@ import java.util.stream.Collectors;
 public final class EdgeGrpcSession implements Closeable {
 
     private static final ReentrantLock downlinkMsgLock = new ReentrantLock();
-    private static final ReentrantLock downlinkMsgsPackLock = new ReentrantLock();
 
     private static final String QUEUE_START_TS_ATTR_KEY = "queueStartTs";
 
@@ -390,15 +389,15 @@ public final class EdgeGrpcSession implements Closeable {
     }
 
     private ListenableFuture<Void> sendDownlinkMsgsPack(List<DownlinkMsg> downlinkMsgsPack) {
-        sendDownlinkMsgsFuture = SettableFuture.create();
-        downlinkMsgsPackLock.lock();
-        try {
-            pendingMsgsMap.clear();
-            downlinkMsgsPack.forEach(msg -> pendingMsgsMap.put(msg.getDownlinkMsgId(), msg));
-            scheduleDownlinkMsgsPackSend(true);
-        } finally {
-            downlinkMsgsPackLock.unlock();
+        if (sendDownlinkMsgsFuture != null && !sendDownlinkMsgsFuture.isDone()) {
+            String erroMsg = "[" + this.sessionId + "] Previous send downdlink future was not properly completed, stopping it now";
+            log.error(erroMsg);
+            sendDownlinkMsgsFuture.setException(new RuntimeException(erroMsg));
         }
+        sendDownlinkMsgsFuture = SettableFuture.create();
+        pendingMsgsMap.clear();
+        downlinkMsgsPack.forEach(msg -> pendingMsgsMap.put(msg.getDownlinkMsgId(), msg));
+        scheduleDownlinkMsgsPackSend(true);
         return sendDownlinkMsgsFuture;
     }
 
diff --git a/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeSyncCursor.java b/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeSyncCursor.java
index 85ef95ee12..cb7916965f 100644
--- a/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeSyncCursor.java
+++ b/application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeSyncCursor.java
@@ -32,6 +32,7 @@ import org.thingsboard.server.service.edge.rpc.fetch.TenantWidgetsBundlesEdgeEve
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.NoSuchElementException;
 
 public class EdgeSyncCursor {
 
@@ -59,13 +60,12 @@ public class EdgeSyncCursor {
     }
 
     public EdgeEventFetcher getNext() {
-        if (hasNext()) {
-            EdgeEventFetcher edgeEventFetcher = fetchers.get(currentIdx);
-            currentIdx++;
-            return edgeEventFetcher;
-        } else {
-            throw new IndexOutOfBoundsException();
+        if (!hasNext()) {
+            throw new NoSuchElementException();
         }
+        EdgeEventFetcher edgeEventFetcher = fetchers.get(currentIdx);
+        currentIdx++;
+        return edgeEventFetcher;
     }
 
     public int getCurrentIdx() {