diff --git a/apps/desktop/src/api/sessions.ts b/apps/desktop/src/api/sessions.ts
index 339449db11..002284af8c 100644
--- a/apps/desktop/src/api/sessions.ts
+++ b/apps/desktop/src/api/sessions.ts
@@ -459,9 +459,9 @@ export function getLatestSessionMessages(
   // (ambient, profile string, or explicit pin). Otherwise refreshes create
   // duplicate tail entries and "Show earlier" cannot resolve the loaded tail.
   // Capture before awaiting: the active gateway may change during the read.
-  const tailScope = { ...connectionScoped(), ...sessionScoped(profile) }
+  const route = { ...connectionScoped(), ...sessionScoped(profile) }
   // Normalize only the lookup key; backfill must replay the original route.
-  const ownerScope = { ...tailScope, connectionId: tailScope.connectionId || ambientOwnerConnectionId() }
+  const owner = { ...route, connectionId: route.connectionId || ambientOwnerConnectionId() }
 
   // includeCompacted: durable display history must include rows preserved by
   // in-place compaction (active=0, compacted=1); without them the transcript
@@ -484,11 +484,11 @@ export function getLatestSessionMessages(
     // untagged read there lands on the ambient profile (`'default'` when
     // none is active). `null` is a custom HERMES_HOME and stays distinct.
     const servedProfile = page.profile === undefined ? getApiRequestProfile() || 'default' : page.profile
-    const resolvedOwnerScope = { ...ownerScope, profile: ownerScope.profile || servedProfile }
-    recordTranscriptTail(id, page, tailScope, resolvedOwnerScope)
+    const resolvedOwner = { ...owner, profile: owner.profile || servedProfile }
+    recordTranscriptTail(id, page, route, resolvedOwner)
 
     if (page.session_id && page.session_id !== id) {
-      recordTranscriptTail(page.session_id, page, tailScope, resolvedOwnerScope)
+      recordTranscriptTail(page.session_id, page, route, resolvedOwner)
     }
 
     return page
diff --git a/apps/desktop/src/store/transcript-tail-cache.ts b/apps/desktop/src/store/transcript-tail-cache.ts
index 04f13898a5..65619d19d2 100644
--- a/apps/desktop/src/store/transcript-tail-cache.ts
+++ b/apps/desktop/src/store/transcript-tail-cache.ts
@@ -23,8 +23,10 @@ import { withUniqueToolCallIdsWithinMessage } from '@/lib/chat-messages'
 //     profile switches in the same window: an unscoped key let profile A's
 //     tail be painted against profile B's backend, which then retried a
 //     session id that does not exist there ("session not found") on every
-//     wake. The scope mirrors the in-memory twin's transcriptTailKey
-//     (transcript-tail.ts). Entries persisted before scoping shipped (v1,
+//     wake. The scope is the REQUEST scope the resume path passes (always a
+//     named profile); the in-memory twin (transcript-tail.ts) keys by the
+//     resolved owner instead and the two are never cross-read. Entries
+//     persisted before scoping shipped (v1,
 //     bare-id keys) carry no owner and are unreachable by construction —
 //     they are swept once per window so a stale tail can never paint again.
 
diff --git a/apps/desktop/src/store/transcript-tail.ts b/apps/desktop/src/store/transcript-tail.ts
index fec325dcdb..9e2443d2f9 100644
--- a/apps/desktop/src/store/transcript-tail.ts
+++ b/apps/desktop/src/store/transcript-tail.ts
@@ -23,8 +23,10 @@ export interface TranscriptTailState {
   /** The last hydration page was exactly the page limit, so older rows
    *  likely exist beyond what the in-memory store holds. */
   possiblyTruncated: boolean
-  /** Owning profile captured at hydration time, so a later backfill routes
-   *  its REST read to the same backend that served the tail. */
+  /** The request route captured at hydration time, replayed verbatim by a
+   *  later backfill so it reaches the backend that served the tail. The
+   *  resolved OWNER is the map key, not this field: an ambient read must stay
+   *  ambient even once the server has named its profile. */
   profile?: TranscriptProfileScope
 }
 
@@ -43,6 +45,8 @@ let transcriptTailOrder: string[] = []
 type TailPage = Pick<SessionMessagesResponse, 'messages' | 'pagination'>
 
 function normalizedScope(profile?: TranscriptProfileScope): { connectionId: string; profile: string } | null {
+  // A bare string is the legacy "named profile" spelling: it always names a
+  // profile, so empty means the default one.
   if (typeof profile === 'string') {
     return { connectionId: '', profile: profile.trim() || 'default' }
   }
@@ -115,21 +119,20 @@ function setTranscriptTailEntry(key: string, state: TranscriptTailState): void {
   $transcriptTailBySessionId.set(next)
 }
 
-/** Record the outcome of a tail hydration (`getLatestSessionMessages`). */
+/** Record the outcome of a tail hydration (`getLatestSessionMessages`).
+ *  `route` is what the request was sent with; `owner` is the resolved backend
+ *  the entry is keyed under (defaults to the route when they coincide). */
 export function recordTranscriptTail(
   storedSessionId: string,
   page: TailPage,
-  profile?: TranscriptProfileScope,
-  ownerScope: TranscriptProfileScope | undefined = profile
+  route?: TranscriptProfileScope,
+  owner: TranscriptProfileScope | undefined = route
 ): void {
   if (!storedSessionId) {
     return
   }
 
-  // Keep request routing separate from the resolved owner used for lookup:
-  // backfill must replay an ambient read even when the server names its profile.
-  const key = transcriptTailKey(storedSessionId, ownerScope)
-  setTranscriptTailEntry(key, tailStateFromPage(page, profile))
+  setTranscriptTailEntry(transcriptTailKey(storedSessionId, owner), tailStateFromPage(page, route))
 }
 
 /** Advance the bookkeeping after one older backfill page landed. */