diff --git a/iOSClient/Assistant/Chat/NCAssistantChatModel.swift b/iOSClient/Assistant/Chat/NCAssistantChatModel.swift
index 06bf1c6330..e29e34e8db 100644
--- a/iOSClient/Assistant/Chat/NCAssistantChatModel.swift
+++ b/iOSClient/Assistant/Chat/NCAssistantChatModel.swift
@@ -63,15 +63,15 @@ class NCAssistantChatModel {
         showRetryResponseGenerationButton = false
         currentSession = nil
 
-            await loadAllMessages()
-            currentSession = await checkChatSession(sessionId: selectedConversation.id)
-            chatMessageTaskId = currentSession?.messageTaskId
+        await loadAllMessages()
+        currentSession = await checkChatSession(sessionId: selectedConversation.id)
+        chatMessageTaskId = currentSession?.messageTaskId
 
-            if messages.last?.isFromHuman == true, chatMessageTaskId == nil, isSending == false {
-                showRetryResponseGenerationButton = true
-            } else if chatMessageTaskId != nil {
-                startPollingForResponse()
-            }
+        if messages.last?.isFromHuman == true, chatMessageTaskId == nil, isSending == false {
+            showRetryResponseGenerationButton = true
+        } else if chatMessageTaskId != nil {
+            startPollingForResponse()
+        }
     }
 
     func generateChatSession() async {
@@ -110,7 +110,8 @@ class NCAssistantChatModel {
 
         let result = await NextcloudKit.shared.checkAssistantChatGeneration(taskId: chatMessageTaskId, sessionId: selectedConversation?.id ?? 0, account: ncSession.account)
 
-        if result.error != .success {
+        // API sends expectation failed error (417) when a message is not ready yet. We should continue polling.
+        if result.error != .success, result.error.errorCode != NCGlobal.shared.errorExpectationFailed {
             stopPolling()
             await showErrorBanner(windowScene: windowScene, title: "_error_", text: "_assistant_error_generate_response_", errorCode: result.error.errorCode)
             return
diff --git a/iOSClient/NCGlobal.swift b/iOSClient/NCGlobal.swift
index 70364d60bd..35425dc0c8 100644
--- a/iOSClient/NCGlobal.swift
+++ b/iOSClient/NCGlobal.swift
@@ -164,6 +164,7 @@ final class NCGlobal: Sendable {
     let errorConflict: Int                      = 409
     let errorPreconditionFailed: Int            = 412
     let errorUnsupportedMediaType: Int          = 415
+    let errorExpectationFailed: Int             = 417
     let errorInternalServerError: Int           = 500
     let errorMaintenance: Int                   = 503
     let errorQuota: Int                         = 507