diff --git a/client/server/server.go b/client/server/server.go
index d84941023..de24d7faa 100644
--- a/client/server/server.go
+++ b/client/server/server.go
@@ -1539,8 +1539,21 @@ func (s *Server) WaitExtendAuthSession(
 		return nil, gstatus.Errorf(codes.InvalidArgument, "invalid device code or no active extend-session flow")
 	}
 
-	tokenInfo, err := oAuthFlow.WaitToken(ctx, authInfo)
+	// Preempt a previous WaitExtendAuthSession (e.g. when the tray
+	// notification and the about-to-expire dialog both start a flow on
+	// the same deadline). The older waiter exits via context.Canceled;
+	// the new one takes over the IdP poll.
+	s.extendAuthSessionFlow.CancelWait()
+
+	waitCtx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	s.extendAuthSessionFlow.SetWaitCancel(cancel)
+
+	tokenInfo, err := oAuthFlow.WaitToken(waitCtx, authInfo)
 	if err != nil {
+		if errors.Is(err, context.Canceled) {
+			return nil, gstatus.Errorf(codes.Canceled, "extend-session flow preempted")
+		}
 		return nil, gstatus.Errorf(codes.Internal, "failed to obtain JWT token: %v", err)
 	}
 
diff --git a/client/ui/authsession/service.go b/client/ui/authsession/service.go
index 8cb423da2..5cc96aca4 100644
--- a/client/ui/authsession/service.go
+++ b/client/ui/authsession/service.go
@@ -6,6 +6,9 @@ import (
 	"context"
 	"time"
 
+	"google.golang.org/grpc/codes"
+	gstatus "google.golang.org/grpc/status"
+
 	"github.com/netbirdio/netbird/client/proto"
 )
 
@@ -34,9 +37,12 @@ type ExtendWaitParams struct {
 
 // ExtendResult carries the refreshed deadline. ExpiresAt is nil when the
 // management server reported the peer is not eligible for session
-// extension.
+// extension. Preempted is true when a newer WaitExtend (e.g. started from
+// another UI surface for the same deadline) took over the IdP poll —
+// callers should treat the call as a no-op rather than a failure.
 type ExtendResult struct {
 	ExpiresAt *time.Time `json:"sessionExpiresAt,omitempty"`
+	Preempted bool       `json:"preempted,omitempty"`
 }
 
 // DaemonConn yields a lazy daemon gRPC client. Mirrors services.DaemonConn
@@ -101,6 +107,9 @@ func (s *Session) WaitExtend(ctx context.Context, p ExtendWaitParams) (ExtendRes
 		UserCode:   p.UserCode,
 	})
 	if err != nil {
+		if st, ok := gstatus.FromError(err); ok && st.Code() == codes.Canceled {
+			return ExtendResult{Preempted: true}, nil
+		}
 		return ExtendResult{}, err
 	}
 
diff --git a/client/ui/frontend/src/modules/session/SessionAboutToExpireDialog.tsx b/client/ui/frontend/src/modules/session/SessionAboutToExpireDialog.tsx
index 1d07b0988..63ba4d2eb 100644
--- a/client/ui/frontend/src/modules/session/SessionAboutToExpireDialog.tsx
+++ b/client/ui/frontend/src/modules/session/SessionAboutToExpireDialog.tsx
@@ -73,10 +73,20 @@ export default function SessionAboutToExpireDialog() {
                     console.debug("OpenURL failed during extend", e);
                 }
             }
-            await Session.WaitExtend({
+            const result = await Session.WaitExtend({
                 deviceCode: start.deviceCode,
                 userCode: start.userCode,
             });
+            if (result.preempted) {
+                // Another UI surface (e.g. the tray "Extend now"
+                // notification action) started a flow for the same
+                // deadline and took over. Keep the dialog open so the
+                // user can re-trigger if the other flow also fails;
+                // a successful extend elsewhere refreshes the deadline
+                // and this window auto-closes when it's no longer
+                // relevant.
+                return;
+            }
             WindowManager.CloseSessionAboutToExpire().catch(console.error);
         } catch (e) {
             await Dialogs.Error({
diff --git a/client/ui/tray.go b/client/ui/tray.go
index 5d1114db4..c677052ba 100644
--- a/client/ui/tray.go
+++ b/client/ui/tray.go
@@ -1391,14 +1391,22 @@ func (t *Tray) runExtendSession() {
 		}
 	}
 
-	if _, err := t.svc.Session.WaitExtend(ctx, services.ExtendWaitParams{
+	result, err := t.svc.Session.WaitExtend(ctx, services.ExtendWaitParams{
 		DeviceCode: start.DeviceCode,
 		UserCode:   start.UserCode,
-	}); err != nil {
+	})
+	if err != nil {
 		log.Warnf("session-warning: WaitExtend failed: %v", err)
 		t.notifyError(t.loc.T("notify.sessionWarning.failed"))
 		return
 	}
+	if result.Preempted {
+		// Another UI surface (e.g. the about-to-expire dialog) started a
+		// flow for the same deadline and took over. Stay silent so the
+		// user only sees the outcome of the surviving flow.
+		log.Debugf("session-warning: WaitExtend preempted by a newer flow")
+		return
+	}
 	t.notify(t.loc.T("notify.sessionWarning.successTitle"), t.loc.T("notify.sessionWarning.successBody"), notifyIDSessionWarning)
 }