diff --git a/docker-compose.e2e.yml b/docker-compose.e2e.yml
index daacaadec..23cdf032b 100644
--- a/docker-compose.e2e.yml
+++ b/docker-compose.e2e.yml
@@ -54,6 +54,11 @@ services:
       - LLM_SERVER_KEY=e2e-dummy-key
       - LLM_SERVER_MODEL=e2e-mock
       - EMBEDDING_PROVIDER=none
+      # Creating a bridge for the nested worker changes the runner's network
+      # topology, which makes Chromium drop the flow's HTTP/WebSocket traffic.
+      # This fixed mock scenario only executes `uname -a`, so it does not need
+      # an isolated worker network.
+      - DOCKER_NETWORK=host
     # The base service has no healthcheck, so `up --wait` would return before
     # goose migrations finish and the API serves. The runtime image is alpine —
     # probe with busybox wget, not curl.
diff --git a/frontend/e2e/mock-llm/scenario.mjs b/frontend/e2e/mock-llm/scenario.mjs
index f845d0ded..4e8cd40bf 100644
--- a/frontend/e2e/mock-llm/scenario.mjs
+++ b/frontend/e2e/mock-llm/scenario.mjs
@@ -104,6 +104,10 @@ export const RULES = [
         ],
     },
     {
+        // Flow creation starts its worker before the mutation returns. Give the
+        // browser time to route to the flow and attach the live log subscriptions
+        // before this fixture emits its only sandbox command and final messages.
+        delayMs: 1_000,
         label: 'agent-terminal',
         match: /"terminal"/,
         toolCalls: [
diff --git a/frontend/e2e/mock-llm/server.mjs b/frontend/e2e/mock-llm/server.mjs
index a8354ada2..ef2070d66 100644
--- a/frontend/e2e/mock-llm/server.mjs
+++ b/frontend/e2e/mock-llm/server.mjs
@@ -4,6 +4,7 @@
 // answers stay deterministic: the whole request JSON is matched against
 // scenario.mjs rules in order, first hit wins.
 import { createServer } from 'node:http';
+import { setTimeout as sleep } from 'node:timers/promises';
 
 import { FALLBACK, RULES } from './scenario.mjs';
 
@@ -143,6 +144,11 @@ createServer(async (request, response) => {
         const toolNames = toolList.map((tool) => tool?.function?.name ?? tool?.type ?? '?').join(',');
 
         console.log(`[mock-llm] ${rule.label}: ${payload.stream ? 'stream' : 'plain'} tools=[${toolNames}]`);
+
+        if (rule.delayMs) {
+            await sleep(rule.delayMs);
+        }
+
         respondCompletion(response, payload, rule);
 
         return;