diff --git a/src/addons/messages/messages.module.ts b/src/addons/messages/messages.module.ts
index c6579af46..9f7748ff0 100644
--- a/src/addons/messages/messages.module.ts
+++ b/src/addons/messages/messages.module.ts
@@ -87,7 +87,7 @@ const preferencesRoutes: Routes = [
                 CoreUserDelegate.registerHandler(AddonMessagesSendMessageUserHandler.instance);
 
                 // Sync some discussions when device goes online.
-                CoreNetwork.onConnect().subscribe(() => {
+                CoreNetwork.onConnectShouldBeStable().subscribe(() => {
                     // Execute the callback in the Angular zone, so change detection doesn't stop working.
                     NgZone.run(() => {
                         AddonMessagesSync.syncAllDiscussions(undefined, true);
diff --git a/src/core/initializers/watch-network.ts b/src/core/initializers/watch-network.ts
index 9d8aabf5f..74c6a0261 100644
--- a/src/core/initializers/watch-network.ts
+++ b/src/core/initializers/watch-network.ts
@@ -16,9 +16,12 @@ import { CoreCronDelegate } from '@services/cron';
 import { NgZone } from '@singletons';
 import { CoreNetwork } from '@services/network';
 
+/**
+ * Initializer function.
+ */
 export default function(): void {
     // When the app is re-connected, start network handlers that were stopped.
-    CoreNetwork.onConnect().subscribe(() => {
+    CoreNetwork.onConnectShouldBeStable().subscribe(() => {
         // Execute the callback in the Angular zone, so change detection doesn't stop working.
         NgZone.run(() => CoreCronDelegate.startNetworkHandlers());
     });
diff --git a/src/core/services/filepool.ts b/src/core/services/filepool.ts
index 1751636f0..3c633823a 100644
--- a/src/core/services/filepool.ts
+++ b/src/core/services/filepool.ts
@@ -150,7 +150,7 @@ export class CoreFilepoolProvider {
             this.checkQueueProcessing();
 
             // Start queue when device goes online.
-            CoreNetwork.onConnect().subscribe(() => {
+            CoreNetwork.onConnectShouldBeStable().subscribe(() => {
                 // Execute the callback in the Angular zone, so change detection doesn't stop working.
                 NgZone.run(() => this.checkQueueProcessing());
             });
diff --git a/src/core/services/network.ts b/src/core/services/network.ts
index aeb49a4ae..b50a87601 100644
--- a/src/core/services/network.ts
+++ b/src/core/services/network.ts
@@ -38,9 +38,11 @@ export class CoreNetworkService extends Network {
     type!: string;
 
     protected connectObservable = new Subject<'connected'>();
+    protected connectStableObservable = new Subject<'connected'>();
     protected disconnectObservable = new Subject<'disconnected'>();
     protected forceConnectionMode?: CoreNetworkConnection;
     protected online = false;
+    protected connectStableTimeout?: number;
 
     get connectionType(): CoreNetworkConnection {
         if (this.forceConnectionMode !== undefined) {
@@ -146,6 +148,7 @@ export class CoreNetworkService extends Network {
     /**
      * Returns an observable to notify when the app is connected.
      * It will also be fired when connection type changes.
+     * If you're going to perform network requests once the device is connected, please use onConnectShouldBeStable instead.
      *
      * @returns Observable.
      */
@@ -153,6 +156,18 @@ export class CoreNetworkService extends Network {
         return this.connectObservable;
     }
 
+    /**
+     * Returns an observable to notify when the app is connected and it should already be a stable a connection.
+     * E.g. when leaving flight mode the device could connect to mobile network first and then to WiFi.
+     * If you're going to perform network requests once the device is connected, it's recommended to use this function instead of
+     * onConnect because some OS (e.g. Android) duplicate a request if the type of connection changes while the request is done.
+     *
+     * @returns Observable.
+     */
+    onConnectShouldBeStable(): Observable<'connected'> {
+        return this.connectStableObservable;
+    }
+
     /**
      * Returns an observable to notify when the app is disconnected.
      *
@@ -166,10 +181,14 @@ export class CoreNetworkService extends Network {
      * Fires the correct observable depending on the connection status.
      */
     protected fireObservable(): void {
+        clearTimeout(this.connectStableTimeout);
         this.checkOnline();
 
         if (this.online) {
             this.connectObservable.next('connected');
+            this.connectStableTimeout = window.setTimeout(() => {
+                this.connectStableObservable.next('connected');
+            }, 5000);
         } else {
             this.disconnectObservable.next('disconnected');
         }
diff --git a/src/core/services/utils/iframe.ts b/src/core/services/utils/iframe.ts
index 3314fc8dc..a35d72194 100644
--- a/src/core/services/utils/iframe.ts
+++ b/src/core/services/utils/iframe.ts
@@ -76,7 +76,7 @@ export class CoreIframeUtilsProvider {
             this.addOfflineWarning(element, src, isSubframe);
 
             // If the network changes, check it again.
-            const subscription = CoreNetwork.onConnect().subscribe(() => {
+            const subscription = CoreNetwork.onConnectShouldBeStable().subscribe(() => {
                 // Execute the callback in the Angular zone, so change detection doesn't stop working.
                 NgZone.run(() => {
                     if (!this.checkOnlineFrameInOffline(element, isSubframe)) {