diff --git a/frontend-modern/public/install-host-agent.ps1 b/frontend-modern/public/install-host-agent.ps1
index c0c14509c..d212c1c65 100644
--- a/frontend-modern/public/install-host-agent.ps1
+++ b/frontend-modern/public/install-host-agent.ps1
@@ -473,7 +473,7 @@ if (-not $NoService) {
             
             for ($i = 1; $i -le $maxRetries; $i++) {
                 Start-Sleep -Seconds $retryDelay
-                $hostname = $env:COMPUTERNAME
+                $hostname = if ($Hostname) { $Hostname } else { $env:COMPUTERNAME }
                 $lookupHost = Test-AgentRegistration -PulseUrl $PulseUrl -Hostname $hostname -Token $Token
                 
                 if ($lookupHost) {
diff --git a/internal/ai/chat/service.go b/internal/ai/chat/service.go
index 3a5f3309e..6b69080a7 100644
--- a/internal/ai/chat/service.go
+++ b/internal/ai/chat/service.go
@@ -773,10 +773,9 @@ func (s *Service) createProviderForModel(modelStr string) (providers.StreamingPr
 	case "ollama":
 		baseURL := s.cfg.OllamaBaseURL
 		if baseURL == "" {
-			// Ollama not explicitly configured. If the user has a custom OpenAI-compatible
-			// base URL set, route there instead — this handles bare model names (e.g.
-			// "qwen3-omni") typed manually for self-hosted OpenAI-compatible endpoints.
-			if s.cfg.OpenAIAPIKey != "" && s.cfg.OpenAIBaseURL != "" {
+			// Only fall back for bare/unrecognized model names (no explicit "ollama:" prefix).
+			// An explicit "ollama:llama3" must not be silently rerouted to a different provider.
+			if !strings.HasPrefix(modelStr, "ollama:") && s.cfg.OpenAIAPIKey != "" && s.cfg.OpenAIBaseURL != "" {
 				return providers.NewOpenAIClient(s.cfg.OpenAIAPIKey, modelName, s.cfg.OpenAIBaseURL, timeout), nil
 			}
 			baseURL = "http://localhost:11434"
diff --git a/internal/api/router.go b/internal/api/router.go
index 0181da78e..62e6abaa6 100644
--- a/internal/api/router.go
+++ b/internal/api/router.go
@@ -3447,11 +3447,26 @@ func (r *Router) StopAIChat(ctx context.Context) {
 // RestartAIChat restarts the AI chat service with updated configuration
 // Call this when AI settings change that affect the service (e.g., model selection)
 func (r *Router) RestartAIChat(ctx context.Context) {
-	if r.aiHandler != nil {
-		if err := r.aiHandler.Restart(ctx); err != nil {
-			log.Error().Err(err).Msg("Failed to restart AI chat service")
-		} else {
-			log.Info().Msg("AI chat service restarted with new configuration")
+	if r.aiHandler == nil {
+		return
+	}
+
+	wasRunning := r.aiHandler.IsRunning(ctx)
+
+	if err := r.aiHandler.Restart(ctx); err != nil {
+		log.Error().Err(err).Msg("Failed to restart AI chat service")
+		return
+	}
+
+	log.Info().Msg("AI chat service restarted with new configuration")
+
+	// If the service just started for the first time (was not running before),
+	// perform the full post-start wiring that StartAIChat normally handles.
+	if !wasRunning && r.aiHandler.IsRunning(ctx) {
+		r.wireAIChatProviders()
+		r.wireChatServiceToAI()
+		if r.aiSettingsHandler != nil {
+			r.aiSettingsHandler.WireOrchestratorAfterChatStart()
 		}
 	}
 }