From 0ec0f8faaf16cef7aa8e1f415d16987b589313c4 Mon Sep 17 00:00:00 2001
From: Danielle Maywood <danielle@themaywoods.com>
Date: Fri, 27 Mar 2026 13:08:58 +0000
Subject: [PATCH] fix: guard per-chat cancelQueries to prevent 'Chat not found'
 race (#23714)

---
 site/src/pages/AgentsPage/AgentsPage.tsx | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/site/src/pages/AgentsPage/AgentsPage.tsx b/site/src/pages/AgentsPage/AgentsPage.tsx
index cb36584680..df704964ba 100644
--- a/site/src/pages/AgentsPage/AgentsPage.tsx
+++ b/site/src/pages/AgentsPage/AgentsPage.tsx
@@ -471,10 +471,17 @@ const AgentsPage: FC = () => {
 					// title generation finished, so its response carries
 					// the fallback title.
 					void cancelChatListQueries(queryClient);
-					void queryClient.cancelQueries({
-						queryKey: chatKey(updatedChat.id),
-						exact: true,
-					});
+					// Only cancel a per-chat refetch when the cache
+					// already has data. Cancelling a first-time fetch
+					// reverts the query to pending/idle with no data
+					// and no retry, which AgentDetail shows as
+					// "Chat not found".
+					if (queryClient.getQueryData(chatKey(updatedChat.id))) {
+						void queryClient.cancelQueries({
+							queryKey: chatKey(updatedChat.id),
+							exact: true,
+						});
+					}
 
 					// For "created" events, use a cross-page existence
 					// check and prepend only to the first page.