diff --git a/quic/core/congestion_control/bbr2_misc.h b/quic/core/congestion_control/bbr2_misc.h
index 8f5d418..14a0882 100644
--- a/quic/core/congestion_control/bbr2_misc.h
+++ b/quic/core/congestion_control/bbr2_misc.h
@@ -92,7 +92,7 @@
 
   // If true, always exit STARTUP on loss, even if bandwidth exceeds threshold.
   // If false, exit STARTUP on loss only if bandwidth is below threshold.
-  bool always_exit_startup_on_excess_loss = true;
+  bool always_exit_startup_on_excess_loss = false;
 
   /*
    * DRAIN parameters.
diff --git a/quic/core/congestion_control/bbr2_sender.cc b/quic/core/congestion_control/bbr2_sender.cc
index d0f6127..b69a795 100644
--- a/quic/core/congestion_control/bbr2_sender.cc
+++ b/quic/core/congestion_control/bbr2_sender.cc
@@ -132,7 +132,7 @@
     params_.ignore_inflight_lo = true;
   }
   if (ContainsQuicTag(connection_options, kB2NE)) {
-    params_.always_exit_startup_on_excess_loss = false;
+    params_.always_exit_startup_on_excess_loss = true;
   }
   if (ContainsQuicTag(connection_options, kB2SL)) {
     params_.startup_loss_exit_use_max_delivered_for_inflight_hi = false;
diff --git a/quic/core/congestion_control/bbr2_simulator_test.cc b/quic/core/congestion_control/bbr2_simulator_test.cc
index e26760e..99acf2c 100644
--- a/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -417,25 +417,6 @@
   EXPECT_APPROX_EQ(params.RTT(), rtt_stats()->smoothed_rtt(), 1.0f);
 }
 
-TEST_F(Bbr2DefaultTopologyTest, SimpleTransferB2NE) {
-  SetConnectionOption(kB2NE);
-  DefaultTopologyParams params;
-  CreateNetwork(params);
-
-  // Transfer 12MB.
-  DoSimpleTransfer(12 * 1024 * 1024, QuicTime::Delta::FromSeconds(35));
-  EXPECT_TRUE(Bbr2ModeIsOneOf({Bbr2Mode::PROBE_BW, Bbr2Mode::PROBE_RTT}));
-
-  EXPECT_APPROX_EQ(params.BottleneckBandwidth(),
-                   sender_->ExportDebugState().bandwidth_hi, 0.01f);
-
-  EXPECT_LE(sender_loss_rate_in_packets(), 0.05);
-  // The margin here is high, because the aggregation greatly increases
-  // smoothed rtt.
-  EXPECT_GE(params.RTT() * 4, rtt_stats()->smoothed_rtt());
-  EXPECT_APPROX_EQ(params.RTT(), rtt_stats()->min_rtt(), 0.2f);
-}
-
 TEST_F(Bbr2DefaultTopologyTest, SimpleTransferB2RC) {
   SetConnectionOption(kB2RC);
   DefaultTopologyParams params;
@@ -859,6 +840,42 @@
   EXPECT_APPROX_EQ(sender_->ExportDebugState().inflight_hi, params.BDP(), 0.1f);
 }
 
+// Verifies that in STARTUP, if we exceed loss threshold in a round, we exit
+// STARTUP at the end of the round even if there's enough bandwidth growth.
+TEST_F(Bbr2DefaultTopologyTest, ExitStartupDueToLossB2NE) {
+  // Set up flags such that any loss will be considered "too high".
+  SetQuicFlag(FLAGS_quic_bbr2_default_startup_full_loss_count, 0);
+  SetQuicFlag(FLAGS_quic_bbr2_default_loss_threshold, 0.0);
+
+  sender_ = SetupBbr2Sender(&sender_endpoint_, /*old_sender=*/nullptr);
+
+  SetConnectionOption(kB2NE);
+  DefaultTopologyParams params;
+  params.switch_queue_capacity_in_bdp = 0.5;
+  CreateNetwork(params);
+
+  // Run until the full bandwidth is reached and check how many rounds it was.
+  sender_endpoint_.AddBytesToTransfer(12 * 1024 * 1024);
+  QuicRoundTripCount max_bw_round = 0;
+  QuicBandwidth max_bw(QuicBandwidth::Zero());
+  bool simulator_result = simulator_.RunUntilOrTimeout(
+      [this, &max_bw, &max_bw_round]() {
+        if (max_bw < sender_->ExportDebugState().bandwidth_hi) {
+          max_bw = sender_->ExportDebugState().bandwidth_hi;
+          max_bw_round = sender_->ExportDebugState().round_trip_count;
+        }
+        return sender_->ExportDebugState().startup.full_bandwidth_reached;
+      },
+      QuicTime::Delta::FromSeconds(5));
+  ASSERT_TRUE(simulator_result);
+  EXPECT_EQ(Bbr2Mode::DRAIN, sender_->ExportDebugState().mode);
+  EXPECT_EQ(sender_->ExportDebugState().round_trip_count, max_bw_round);
+  EXPECT_EQ(
+      0u,
+      sender_->ExportDebugState().startup.round_trips_without_bandwidth_growth);
+  EXPECT_NE(0u, sender_connection_stats().packets_lost);
+}
+
 TEST_F(Bbr2DefaultTopologyTest, SenderPoliced) {
   DefaultTopologyParams params;
   params.sender_policer_params = TrafficPolicerParams();
diff --git a/quic/core/congestion_control/bbr2_startup.cc b/quic/core/congestion_control/bbr2_startup.cc
index 5a9a532..1bd89c6 100644
--- a/quic/core/congestion_control/bbr2_startup.cc
+++ b/quic/core/congestion_control/bbr2_startup.cc
@@ -112,8 +112,9 @@
         new_inflight_hi = model_->max_bytes_delivered_in_round();
       }
     }
-    QUIC_DVLOG(3) << sender_ << " Exiting STARTUP due to loss. inflight_hi:"
-                  << new_inflight_hi;
+    QUIC_DVLOG(3) << sender_ << " Exiting STARTUP due to loss at round "
+                  << model_->RoundTripCount()
+                  << ". inflight_hi:" << new_inflight_hi;
     // TODO(ianswett): Add a shared method to set inflight_hi in the model.
     model_->set_inflight_hi(new_inflight_hi);
     model_->set_full_bandwidth_reached();
diff --git a/quic/core/crypto/crypto_protocol.h b/quic/core/crypto/crypto_protocol.h
index e08d90b..8a86255 100644
--- a/quic/core/crypto/crypto_protocol.h
+++ b/quic/core/crypto/crypto_protocol.h
@@ -127,9 +127,10 @@
 const QuicTag kB2ON = TAG('B', '2', 'O', 'N');   // Enable BBRv2
 const QuicTag kB2NA = TAG('B', '2', 'N', 'A');   // For BBRv2, do not add ack
                                                  // height to queueing threshold
-const QuicTag kB2NE = TAG('B', '2', 'N', 'E');   // For BBRv2, do not exit
-                                                 // STARTUP if there's enough
-                                                 // bandwidth growth
+const QuicTag kB2NE = TAG('B', '2', 'N', 'E');   // For BBRv2, always exit
+                                                 // STARTUP on loss, even if
+                                                 // bandwidth growth exceeds
+                                                 // threshold.
 const QuicTag kB2RP = TAG('B', '2', 'R', 'P');   // For BBRv2, run PROBE_RTT on
                                                  // the regular schedule
 const QuicTag kB2CL = TAG('B', '2', 'C', 'L');   // For BBRv2, allow PROBE_BW