diff --git a/ts/background.ts b/ts/background.ts
index dd902c610..010dd7735 100644
--- a/ts/background.ts
+++ b/ts/background.ts
@@ -2778,9 +2778,11 @@ export async function startApp(): Promise<void> {
     }
 
     await conversation.updateExpirationTimer(expireTimer, {
+      // Note: because it's our conversationId, this notification will be marked read. But
+      //   setting this will make 'isSetByOther' check true.
+      source: window.ConversationController.getOurConversationId(),
       fromSync: true,
       receivedAt: ev.receivedAtCounter,
-      source: window.ConversationController.getOurConversationId(),
       reason: 'group sync',
     });
   }
diff --git a/ts/models/conversations.ts b/ts/models/conversations.ts
index d69feaa53..d2b6ccb35 100644
--- a/ts/models/conversations.ts
+++ b/ts/models/conversations.ts
@@ -4428,7 +4428,9 @@ export class ConversationModel extends window.Backbone
       }
     }
 
-    source = source || window.ConversationController.getOurConversationId();
+    const ourConversationId =
+      window.ConversationController.getOurConversationId();
+    source = source || ourConversationId;
 
     this.set({ expireTimer });
 
@@ -4442,8 +4444,13 @@ export class ConversationModel extends window.Backbone
     //   to be above the message that initiated that change, hence the subtraction.
     const sentAt = (providedSentAt || receivedAtMS) - 1;
 
+    const isFromSyncOperation =
+      reason === 'group sync' || reason === 'contact sync';
+    const isFromMe =
+      window.ConversationController.get(source)?.id === ourConversationId;
     const isNoteToSelf = isMe(this.attributes);
-    const shouldBeRead = isNoteToSelf || isInitialSync;
+    const shouldBeRead =
+      (isInitialSync && isFromSyncOperation) || isFromMe || isNoteToSelf;
 
     const model = new window.Whisper.Message({
       conversationId: this.id,
diff --git a/ts/models/messages.ts b/ts/models/messages.ts
index 6bddb730b..48019a971 100644
--- a/ts/models/messages.ts
+++ b/ts/models/messages.ts
@@ -2663,7 +2663,7 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
             //   point and these calls will return early.
             if (dataMessage.expireTimer) {
               conversation.updateExpirationTimer(dataMessage.expireTimer, {
-                source,
+                source: sourceUuid || source,
                 receivedAt: message.get('received_at'),
                 receivedAtMS: message.get('received_at_ms'),
                 sentAt: message.get('sent_at'),
@@ -2676,7 +2676,7 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
               !isEndSession(message.attributes)
             ) {
               conversation.updateExpirationTimer(undefined, {
-                source,
+                source: sourceUuid || source,
                 receivedAt: message.get('received_at'),
                 receivedAtMS: message.get('received_at_ms'),
                 sentAt: message.get('sent_at'),
diff --git a/ts/services/contactSync.ts b/ts/services/contactSync.ts
index abf136cb0..c4d89b1a2 100644
--- a/ts/services/contactSync.ts
+++ b/ts/services/contactSync.ts
@@ -61,6 +61,8 @@ async function updateConversationFromContactSync(
 
   // expireTimer isn't in Storage Service so we have to rely on contact sync.
   await conversation.updateExpirationTimer(details.expireTimer, {
+    // Note: because it's our conversationId, this notification will be marked read. But
+    //   setting this will make 'isSetByOther' check true.
     source: window.ConversationController.getOurConversationId(),
     receivedAt: receivedAtCounter,
     fromSync: true,