diff --git a/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx b/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
index 0de5fd272..0992c3b17 100644
--- a/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
+++ b/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
@@ -131,7 +131,14 @@ export function AgentSessionThreadPanel({
       : `Last updated ${new Date(latestActivityAt).toLocaleString()}`;
 
   const { fetchOlderArchived, hasOlderArchived } =
-    useLoadArchivedObserverEvents(isLive, sessionChannelId ?? null);
+    useLoadArchivedObserverEvents(
+      // Archive history must load regardless of live status — an idle agent's
+      // channel should still show its archived observer history. Enable whenever
+      // there is a resolved sessionChannelId (the hook's owner_p guard handles
+      // the case where no save subscription exists).
+      Boolean(sessionChannelId),
+      sessionChannelId ?? null,
+    );
 
   useLoadOlderOnScroll({
     fetchOlder: fetchOlderArchived,
diff --git a/desktop/src/features/channels/ui/useChannelAgentSessions.ts b/desktop/src/features/channels/ui/useChannelAgentSessions.ts
index 2f4be2f16..8420c3732 100644
--- a/desktop/src/features/channels/ui/useChannelAgentSessions.ts
+++ b/desktop/src/features/channels/ui/useChannelAgentSessions.ts
@@ -220,9 +220,14 @@ export function useChannelAgentSessions({
       setThreadReplyTargetId(null);
       setChannelManagementOpen(false);
       setOpenAgentSessionPubkey(pubkey);
-      setOpenAgentSessionChannelId(channelId ?? null);
+      // Fall back to activeChannelId so opening from within a channel always
+      // scopes the panel to that channel — even when no explicit channelId is
+      // supplied (e.g. activity-list click). Without this, a null channelId
+      // bypasses scopeByChannel and lets all channels' live frames through.
+      setOpenAgentSessionChannelId(channelId ?? activeChannelId ?? null);
     },
     [
+      activeChannelId,
       isAgentSessionOpen,
       openThreadHeadId,
       profilePanelPubkey,
@@ -260,9 +265,11 @@ export function useChannelAgentSessions({
   const selectAgentSession = React.useCallback(
     (pubkey: string, channelId?: string | null) => {
       setOpenAgentSessionPubkey(pubkey);
-      setOpenAgentSessionChannelId(channelId ?? null);
+      // Same fallback as openAgentSession: use activeChannelId when the caller
+      // omits channelId, so the panel is always scoped to the current channel.
+      setOpenAgentSessionChannelId(channelId ?? activeChannelId ?? null);
     },
-    [setOpenAgentSessionChannelId, setOpenAgentSessionPubkey],
+    [activeChannelId, setOpenAgentSessionChannelId, setOpenAgentSessionPubkey],
   );
 
   const openThreadAndCloseAgentSession = React.useCallback(