diff --git a/lib/shared/thread-actions-utils.js b/lib/shared/thread-actions-utils.js
--- a/lib/shared/thread-actions-utils.js
+++ b/lib/shared/thread-actions-utils.js
@@ -125,7 +125,7 @@
     );
     if (threadTypeIsThick(threadInfo.type)) {
       const type = assertThickThreadType(
-        pendingThreadType(otherMemberIDs.length),
+        pendingThreadType(otherMemberIDs.length, 'thick'),
       );
 
       invariant(
@@ -140,7 +140,7 @@
       });
     } else {
       const type = assertThinThreadType(
-        pendingThreadType(otherMemberIDs.length),
+        pendingThreadType(otherMemberIDs.length, 'thin'),
       );
 
       invariant(
diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -693,8 +693,9 @@
 
 function pendingThreadType(
   numberOfOtherMembers: number,
+  thickOrThin: 'thick' | 'thin',
 ): 4 | 6 | 7 | 13 | 14 | 15 {
-  if (usingOlmViaTunnelbrokerForDMs) {
+  if (usingOlmViaTunnelbrokerForDMs && thickOrThin === 'thick') {
     if (numberOfOtherMembers === 0) {
       return threadTypes.PRIVATE;
     } else if (numberOfOtherMembers === 1) {
@@ -1268,7 +1269,7 @@
       const { sourceMessageID } = baseThreadInfo;
       const pendingThreadID = searching
         ? getPendingThreadID(
-            pendingThreadType(userInfoInputArray.length),
+            pendingThreadType(userInfoInputArray.length, 'thin'),
             [...userInfoInputArray.map(user => user.id), viewerID],
             sourceMessageID,
           )
@@ -1286,7 +1287,7 @@
       const updatedThread = searching
         ? createPendingThread({
             viewerID,
-            threadType: pendingThreadType(userInfoInputArray.length),
+            threadType: pendingThreadType(userInfoInputArray.length, 'thick'),
             members: [loggedInUserInfo, ...userInfoInputArray],
           })
         : baseThreadInfo;
diff --git a/native/chat/message-list-container.react.js b/native/chat/message-list-container.react.js
--- a/native/chat/message-list-container.react.js
+++ b/native/chat/message-list-container.react.js
@@ -167,7 +167,10 @@
         parentThreadHeader = (
           <ParentThreadHeader
             parentThreadInfo={genesisThreadInfo}
-            childThreadType={pendingThreadType(userInfoInputArray.length)}
+            childThreadType={pendingThreadType(
+              userInfoInputArray.length,
+              'thin',
+            )}
           />
         );
       }