diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 47bde72..1d5d8af 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -4622,9 +4622,16 @@
     }
 
     private void updateAvoidBadWifi() {
+        ensureRunningOnConnectivityServiceThread();
+        // Agent info scores and offer scores depend on whether cells yields to bad wifi.
         for (final NetworkAgentInfo nai : mNetworkAgentInfos) {
             nai.updateScoreForNetworkAgentUpdate();
         }
+        // UpdateOfferScore will update mNetworkOffers inline, so make a copy first.
+        final ArrayList<NetworkOfferInfo> offersToUpdate = new ArrayList<>(mNetworkOffers);
+        for (final NetworkOfferInfo noi : offersToUpdate) {
+            updateOfferScore(noi.offer);
+        }
         rematchAllNetworksAndRequests();
     }
 
@@ -6413,11 +6420,23 @@
         Objects.requireNonNull(score);
         Objects.requireNonNull(caps);
         Objects.requireNonNull(callback);
+        final boolean yieldToBadWiFi = caps.hasTransport(TRANSPORT_CELLULAR) && !avoidBadWifi();
         final NetworkOffer offer = new NetworkOffer(
-                FullScore.makeProspectiveScore(score, caps), caps, callback, providerId);
+                FullScore.makeProspectiveScore(score, caps, yieldToBadWiFi),
+                caps, callback, providerId);
         mHandler.sendMessage(mHandler.obtainMessage(EVENT_REGISTER_NETWORK_OFFER, offer));
     }
 
+    private void updateOfferScore(final NetworkOffer offer) {
+        final boolean yieldToBadWiFi =
+                offer.caps.hasTransport(TRANSPORT_CELLULAR) && !avoidBadWifi();
+        final NetworkOffer newOffer = new NetworkOffer(
+                offer.score.withYieldToBadWiFi(yieldToBadWiFi),
+                        offer.caps, offer.callback, offer.providerId);
+        if (offer.equals(newOffer)) return;
+        handleRegisterNetworkOffer(newOffer);
+    }
+
     @Override
     public void unofferNetwork(@NonNull final INetworkOfferCallback callback) {
         mHandler.sendMessage(mHandler.obtainMessage(EVENT_UNREGISTER_NETWORK_OFFER, callback));
@@ -6838,6 +6857,7 @@
      * @param newOffer The new offer. If the callback member is the same as an existing
      *                 offer, it is an update of that offer.
      */
+    // TODO : rename this to handleRegisterOrUpdateNetworkOffer
     private void handleRegisterNetworkOffer(@NonNull final NetworkOffer newOffer) {
         ensureRunningOnConnectivityServiceThread();
         if (!isNetworkProviderWithIdRegistered(newOffer.providerId)) {
@@ -6852,6 +6872,14 @@
         if (null != existingOffer) {
             handleUnregisterNetworkOffer(existingOffer);
             newOffer.migrateFrom(existingOffer.offer);
+            if (DBG) {
+                // handleUnregisterNetworkOffer has already logged the old offer
+                log("update offer from providerId " + newOffer.providerId + " new : " + newOffer);
+            }
+        } else {
+            if (DBG) {
+                log("register offer from providerId " + newOffer.providerId + " : " + newOffer);
+            }
         }
         final NetworkOfferInfo noi = new NetworkOfferInfo(newOffer);
         try {
@@ -6866,6 +6894,9 @@
 
     private void handleUnregisterNetworkOffer(@NonNull final NetworkOfferInfo noi) {
         ensureRunningOnConnectivityServiceThread();
+        if (DBG) {
+            log("unregister offer from providerId " + noi.offer.providerId + " : " + noi.offer);
+        }
         mNetworkOffers.remove(noi);
         noi.offer.callback.asBinder().unlinkToDeath(noi, 0 /* flags */);
     }
diff --git a/service/src/com/android/server/connectivity/FullScore.java b/service/src/com/android/server/connectivity/FullScore.java
index 14cec09..aebb80d 100644
--- a/service/src/com/android/server/connectivity/FullScore.java
+++ b/service/src/com/android/server/connectivity/FullScore.java
@@ -183,7 +183,7 @@
      * @return a FullScore appropriate for comparing to actual network's scores.
      */
     public static FullScore makeProspectiveScore(@NonNull final NetworkScore score,
-            @NonNull final NetworkCapabilities caps) {
+            @NonNull final NetworkCapabilities caps, final boolean yieldToBadWiFi) {
         // If the network offers Internet access, it may validate.
         final boolean mayValidate = caps.hasCapability(NET_CAPABILITY_INTERNET);
         // VPN transports are known in advance.
@@ -197,8 +197,6 @@
         final boolean everUserSelected = false;
         // Don't assume the user will accept unvalidated connectivity.
         final boolean acceptUnvalidated = false;
-        // Don't assume clinging to bad wifi
-        final boolean yieldToBadWiFi = false;
         // A prospective score is invincible if the legacy int in the filter is over the maximum
         // score.
         final boolean invincible = score.getLegacyInt() > NetworkRanker.LEGACY_INT_MAX;
@@ -259,6 +257,16 @@
     }
 
     /**
+     * Returns this score but with the specified yield to bad wifi policy.
+     */
+    public FullScore withYieldToBadWiFi(final boolean newYield) {
+        return new FullScore(mLegacyInt,
+                newYield ? mPolicies | (1L << POLICY_YIELD_TO_BAD_WIFI)
+                        : mPolicies & ~(1L << POLICY_YIELD_TO_BAD_WIFI),
+                mKeepConnectedReason);
+    }
+
+    /**
      * Returns this score but validated.
      */
     public FullScore asValidated() {
diff --git a/service/src/com/android/server/connectivity/NetworkAgentInfo.java b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
index bbf523a..6426f86 100644
--- a/service/src/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
@@ -1187,6 +1187,7 @@
                         ? " underlying{" + Arrays.toString(declaredUnderlyingNetworks) + "}" : "")
                 + "  lp{" + linkProperties + "}"
                 + "  nc{" + networkCapabilities + "}"
+                + "  factorySerialNumber=" + factorySerialNumber
                 + "}";
     }