diff --git a/frontend/src/shared/state/agentsSlice.ts b/frontend/src/shared/state/agentsSlice.ts
index c3d9d715..5be9f50a 100644
--- a/frontend/src/shared/state/agentsSlice.ts
+++ b/frontend/src/shared/state/agentsSlice.ts
@@ -1227,27 +1227,33 @@ const agentsSlice = createSlice({
       .addCase(fetchSession.fulfilled, (state, action) => {
         const session = action.payload;
         const existing = state.sessions[session.id];
-        // Preserve optimistic-pending messages the server snapshot doesn't carry
-        // yet. On remount mid-stream (leave the chat + come back) this fetch's
-        // snapshot predates the just-sent user turn, so a blind replace wiped the
-        // user's own message bubble while the assistant stream (separate slice)
-        // kept going. Carry forward any local pending message not already echoed
-        // in the snapshot; the WS echo / next fetch dedupes it by client_message_id.
+        // Preserve local messages the server snapshot doesn't carry yet. On
+        // remount mid-stream (leave the chat + come back) this fetch's snapshot
+        // predates the just-sent user turn, so a blind replace wiped the user's
+        // own bubble while the assistant stream (separate slice) kept going.
+        // The WS echo clears optimistic_status the instant it arrives, so the
+        // message is usually "confirmed but not yet server-persisted" rather than
+        // still 'pending' (that's why a pending-only filter missed it). Gate on
+        // the session being LIVE: on a running/streaming session, carry forward
+        // any local message the snapshot lacks; on a settled session the snapshot
+        // is authoritative (so a server-side delete isn't resurrected).
         const incomingMsgs = session.messages ?? [];
+        const liveStatus = session.status === 'running' || session.status === 'waiting_approval';
         const incomingClientIds = new Set(
           incomingMsgs.map((m) => m.client_message_id).filter(Boolean),
         );
         const incomingIds = new Set(incomingMsgs.map((m) => m.id));
-        const survivingOptimistic = (existing?.messages ?? []).filter(
-          (m) =>
-            m.optimistic_status === 'pending' &&
-            !(m.client_message_id && incomingClientIds.has(m.client_message_id)) &&
-            !incomingIds.has(m.id),
-        );
+        const surviving = liveStatus
+          ? (existing?.messages ?? []).filter(
+              (m) =>
+                !incomingIds.has(m.id) &&
+                !(m.client_message_id && incomingClientIds.has(m.client_message_id)),
+            )
+          : [];
         state.sessions[session.id] = {
           ...session,
-          messages: survivingOptimistic.length
-            ? [...incomingMsgs, ...survivingOptimistic]
+          messages: surviving.length
+            ? [...incomingMsgs, ...surviving]
             : incomingMsgs,
           pending_approvals: session.pending_approvals ?? existing?.pending_approvals ?? [],
           tool_group_meta: session.tool_group_meta ?? existing?.tool_group_meta ?? {},