diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 8cf8f51..d80efdd 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -5556,12 +5556,20 @@
         }
     }
 
-    public void setImsRegistrationState(boolean registered) {
+    /**
+     * Sets the ims registration state on all valid {@link Phone}s.
+     */
+    public void setImsRegistrationState(final boolean registered) {
         enforceModifyPermission();
 
         final long identity = Binder.clearCallingIdentity();
         try {
-            getDefaultPhone().setImsRegistrationState(registered);
+            // NOTE: Before S, this method only set the default phone.
+            for (final Phone phone : PhoneFactory.getPhones()) {
+                if (SubscriptionManager.isValidSubscriptionId(phone.getSubId())) {
+                    phone.setImsRegistrationState(registered);
+                }
+            }
         } finally {
             Binder.restoreCallingIdentity(identity);
         }
diff --git a/src/com/android/services/telephony/rcs/UceControllerManager.java b/src/com/android/services/telephony/rcs/UceControllerManager.java
index d1f91d1..09288f1 100644
--- a/src/com/android/services/telephony/rcs/UceControllerManager.java
+++ b/src/com/android/services/telephony/rcs/UceControllerManager.java
@@ -51,6 +51,7 @@
     private final ExecutorService mExecutorService;
 
     private volatile UceController mUceController;
+    private volatile RcsFeatureManager mRcsFeatureManager;
 
     public UceControllerManager(Context context, int slotId, int subId) {
         Log.d(LOG_TAG, "create: slotId=" + slotId + ", subId=" + subId);
@@ -74,12 +75,18 @@
 
     @Override
     public void onRcsConnected(RcsFeatureManager manager) {
-        mExecutorService.submit(() -> mUceController.onRcsConnected(manager));
+        mExecutorService.submit(() -> {
+            mRcsFeatureManager = manager;
+            mUceController.onRcsConnected(manager);
+        });
     }
 
     @Override
     public void onRcsDisconnected() {
-        mExecutorService.submit(() -> mUceController.onRcsDisconnected());
+        mExecutorService.submit(() -> {
+            mRcsFeatureManager = null;
+            mUceController.onRcsDisconnected();
+        });
     }
 
     @Override
@@ -103,6 +110,12 @@
             // Destroy existing UceController and create a new one.
             mUceController.onDestroy();
             mUceController = new UceController(mContext, subId);
+
+            // The RCS should be connected when the mRcsFeatureManager is not null. Set it to the
+            // new UceController instance.
+            if (mRcsFeatureManager != null) {
+                mUceController.onRcsConnected(mRcsFeatureManager);
+            }
         });
     }