diff --git a/ts/SignalProtocolStore.ts b/ts/SignalProtocolStore.ts
index 6c3cac8a8d8c..f669d8bf28ab 100644
--- a/ts/SignalProtocolStore.ts
+++ b/ts/SignalProtocolStore.ts
@@ -967,13 +967,17 @@ export class SignalProtocolStore extends EventsMixin {
           conversationIds.has(session.fromDB.conversationId)
         );
         const openEntries: Array<
-          SessionCacheEntry | undefined
+          | undefined
+          | {
+              entry: SessionCacheEntry;
+              record: SessionRecord;
+            }
         > = await Promise.all(
           entries.map(async entry => {
             if (entry.hydrated) {
               const record = entry.item;
               if (record.hasCurrentState()) {
-                return entry;
+                return { record, entry };
               }
 
               return undefined;
@@ -981,7 +985,7 @@ export class SignalProtocolStore extends EventsMixin {
 
             const record = await this._maybeMigrateSession(entry.fromDB);
             if (record.hasCurrentState()) {
-              return entry;
+              return { record, entry };
             }
 
             return undefined;
@@ -989,10 +993,11 @@ export class SignalProtocolStore extends EventsMixin {
         );
 
         const devices = openEntries
-          .map(entry => {
-            if (!entry) {
+          .map(item => {
+            if (!item) {
               return undefined;
             }
+            const { entry, record } = item;
 
             const { conversationId } = entry.fromDB;
             conversationIds.delete(conversationId);
@@ -1015,9 +1020,12 @@ export class SignalProtocolStore extends EventsMixin {
               );
             }
 
+            const registrationId = record.remoteRegistrationId();
+
             return {
               identifier,
               id,
+              registrationId,
             };
           })
           .filter(isNotNil);
diff --git a/ts/test-electron/SignalProtocolStore_test.ts b/ts/test-electron/SignalProtocolStore_test.ts
index 81ea8dd2b238..faa5a3842e94 100644
--- a/ts/test-electron/SignalProtocolStore_test.ts
+++ b/ts/test-electron/SignalProtocolStore_test.ts
@@ -1330,18 +1330,22 @@ describe('SignalProtocolStore', () => {
           {
             id: 1,
             identifier: number,
+            registrationId: 243,
           },
           {
             id: 2,
             identifier: number,
+            registrationId: 243,
           },
           {
             id: 3,
             identifier: number,
+            registrationId: 243,
           },
           {
             id: 10,
             identifier: number,
+            registrationId: 243,
           },
         ],
         emptyIdentifiers: ['blah', 'blah2'],
diff --git a/ts/test-electron/util/sendToGroup_test.ts b/ts/test-electron/util/sendToGroup_test.ts
index bb695d93f471..f55b2eb4bb73 100644
--- a/ts/test-electron/util/sendToGroup_test.ts
+++ b/ts/test-electron/util/sendToGroup_test.ts
@@ -14,14 +14,17 @@ describe('sendToGroup', () => {
         {
           identifier: 'ident-guid-one',
           id: 1,
+          registrationId: 11,
         },
         {
           identifier: 'ident-guid-one',
           id: 2,
+          registrationId: 22,
         },
         {
           identifier: 'ident-guid-two',
           id: 2,
+          registrationId: 33,
         },
       ];
     }
@@ -60,10 +63,12 @@ describe('sendToGroup', () => {
         {
           identifier: 'ident-guid-one',
           id: 2,
+          registrationId: 22,
         },
         {
           identifier: 'ident-guid-two',
           id: 2,
+          registrationId: 33,
         },
       ]);
       assert.deepEqual(newToMemberUuids, ['ident-guid-one', 'ident-guid-two']);
@@ -90,10 +95,12 @@ describe('sendToGroup', () => {
         {
           identifier: 'ident-guid-one',
           id: 2,
+          registrationId: 22,
         },
         {
           identifier: 'ident-guid-two',
           id: 2,
+          registrationId: 33,
         },
       ]);
       assert.deepEqual(removedFromMemberUuids, [
diff --git a/ts/textsecure/Types.d.ts b/ts/textsecure/Types.d.ts
index dfa357b5e8fb..9c25fb9cac05 100644
--- a/ts/textsecure/Types.d.ts
+++ b/ts/textsecure/Types.d.ts
@@ -32,6 +32,7 @@ export type WebAPICredentials = {
 export type DeviceType = {
   id: number;
   identifier: string;
+  registrationId: number;
 };
 
 // How the legacy APIs generate these types
diff --git a/ts/util/sendToGroup.ts b/ts/util/sendToGroup.ts
index 746c52992044..c161ca5c0a70 100644
--- a/ts/util/sendToGroup.ts
+++ b/ts/util/sendToGroup.ts
@@ -44,7 +44,7 @@ import {
 } from '../textsecure/WebAPI';
 import { SignalService as Proto } from '../protobuf';
 
-import { assert } from './assert';
+import { strictAssert } from './assert';
 import { isGroupV2 } from './whatTypeOfConversation';
 
 const ERROR_EXPIRED_OR_MISSING_DEVICES = 409;
@@ -56,7 +56,7 @@ const DAY = 24 * HOUR;
 const MAX_CONCURRENCY = 5;
 
 // sendWithSenderKey is recursive, but we don't want to loop back too many times.
-const MAX_RECURSION = 5;
+const MAX_RECURSION = 10;
 
 // TODO: remove once we move away from ArrayBuffers
 const FIXMEU8 = Uint8Array;
@@ -80,7 +80,7 @@ export async function sendToGroup({
   sendOptions?: SendOptionsType;
   sendType: SendTypesType;
 }): Promise<CallbackResultType> {
-  assert(
+  strictAssert(
     window.textsecure.messaging,
     'sendToGroup: textsecure.messaging not available!'
   );
@@ -133,7 +133,7 @@ export async function sendContentMessageToGroup({
   timestamp: number;
 }): Promise<CallbackResultType> {
   const logId = conversation.idForLogging();
-  assert(
+  strictAssert(
     window.textsecure.messaging,
     'sendContentMessageToGroup: textsecure.messaging not available!'
   );
@@ -247,7 +247,7 @@ export async function sendToGroupViaSenderKey(options: {
     );
   }
 
-  assert(
+  strictAssert(
     window.textsecure.messaging,
     'sendToGroupViaSenderKey: textsecure.messaging not available!'
   );
@@ -293,14 +293,14 @@ export async function sendToGroupViaSenderKey(options: {
   ) {
     await fetchKeysForIdentifiers(emptyIdentifiers);
 
-    // Restart here to capture devices for accounts we just started sesions with
+    // Restart here to capture devices for accounts we just started sessions with
     return sendToGroupViaSenderKey({
       ...options,
       recursionCount: recursionCount + 1,
     });
   }
 
-  assert(
+  strictAssert(
     attributes.senderKeyInfo,
     `sendToGroupViaSenderKey/${logId}: expect senderKeyInfo`
   );
@@ -380,6 +380,13 @@ export async function sendToGroupViaSenderKey(options: {
       ),
       { messageIds: [], sendType: 'senderKeyDistributionMessage' }
     );
+
+    // Restart here because we might have discovered new or dropped devices as part of
+    //   distributing our sender key.
+    return sendToGroupViaSenderKey({
+      ...options,
+      recursionCount: recursionCount + 1,
+    });
   }
 
   // 9. Update memberDevices with both adds and the removals which didn't require a reset.
@@ -696,7 +703,7 @@ async function handle410Response(
           //   been re-registered or re-linked.
           const senderKeyInfo = conversation.get('senderKeyInfo');
           if (senderKeyInfo) {
-            const devicesToRemove: Array<DeviceType> = devices.staleDevices.map(
+            const devicesToRemove: Array<PartialDeviceType> = devices.staleDevices.map(
               id => ({ id, identifier: uuid })
             );
             conversation.set({
@@ -705,7 +712,7 @@ async function handle410Response(
                 memberDevices: differenceWith(
                   senderKeyInfo.memberDevices,
                   devicesToRemove,
-                  deviceComparator
+                  partialDeviceComparator
                 ),
               },
             });
@@ -732,7 +739,7 @@ function getXorOfAccessKeys(devices: Array<DeviceType>): Buffer {
   const uuids = getUuidsFromDevices(devices);
 
   const result = Buffer.alloc(ACCESS_KEY_LENGTH);
-  assert(
+  strictAssert(
     result.length === ACCESS_KEY_LENGTH,
     'getXorOfAccessKeys starting value'
   );
@@ -876,6 +883,21 @@ function isValidSenderKeyRecipient(
 }
 
 function deviceComparator(left?: DeviceType, right?: DeviceType): boolean {
+  return Boolean(
+    left &&
+      right &&
+      left.id === right.id &&
+      left.identifier === right.identifier &&
+      left.registrationId === right.registrationId
+  );
+}
+
+type PartialDeviceType = Omit<DeviceType, 'registrationId'>;
+
+function partialDeviceComparator(
+  left?: PartialDeviceType,
+  right?: PartialDeviceType
+): boolean {
   return Boolean(
     left &&
       right &&