Agent Window is so laggy when having multiple sessions running

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

in Agent Window, when having 1 session running, it’s fine.

but when I start to open 2/3/4 sessions, it becomes very slow, start throwing error “agent does not response in time…”.

I can also clearly see the slowless when switch between session to see progress.

my env:
Version: 3.1.15
VSCode Version: 1.105.1
Commit: 3a67af7b780e0bfc8d32aefa96b8ff1cb8817f80
Date: 2026-04-15T01:46:06.515Z
Layout: glass
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0

I’m using Macbook M4, assume it’s strong enough for these TS pet projects.

the Window Agent is built to handle multiple sessions, but eventually I almost can only use 1 session smoothly, which destroys the purpose of having Window Agent

Steps to Reproduce

Open multiple sessions

Operating System

MacOS

Version Information

Version: 3.1.15
VSCode Version: 1.105.1
Commit: 3a67af7b780e0bfc8d32aefa96b8ff1cb8817f80
Date: 2026-04-15T01:46:06.515Z
Layout: glass
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 25.3.0

Does this stop you from using Cursor

Yes - Cursor is unusable

6

Hey! Thanks for the report.

This is a known issue where running multiple concurrent sessions in the Agents Window can cause the timeout errors you’re seeing. The team is actively aware and working on improving multi-session performance.

A couple of things that may help reduce the frequency in the meantime:

  1. Keep active concurrent sessions to 2 or fewer — The timeout risk increases significantly with 3+ sessions running simultaneously

  2. Close the sidebar when switching between sessions — This reduces the amount of work the UI needs to do on each switch, which helps with the lag you’re noticing

I know these aren’t great workarounds given the whole point of the Agents Window is parallel sessions. That’s exactly why this is a priority for the team.