Agent Window messages are lost if any preceding messages in the conversation were sent via sidebar

Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Agent Window messages are lost if any preceding messages in the conversation were sent via sidebar

Steps to Reproduce

  1. Start a conversation, either in the sidebar or in the Agent Window
  2. Send at least one message in the conversation from the sidebar chat
  3. Pop the conversation out to an Agent Window
  4. Send additional messages in the Agent Window
  5. Close the Agent Window
  6. Return to sidebar/main window
  7. Observe that only messages sent in the sidebar persist; all Agent Window messages since the last sidebar message are lost. If they’re not, repeat steps 2-6; sometimes it takes two pop-out cycles to trigger the bug.

Expected Behavior

All messages should persist regardless of whether they were sent in the sidebar or Agent Window. The conversation history should be unified across both interfaces.

Screenshots

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image1920×1065 65.8 KB

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image1617×1666 221 KB

Operating System

MacOS
Linux

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.54
VSCode Version: 1.99.3
Commit: 5c17eb2968a37f66bc6662f48d6356a100b67be0
Date: 2025-10-21T19:07:38.476Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.6.0

Additional Information

Bug reproduces both on remote connections to a linux box and locally on MacOS. The issue appears related to repeated transitions between sidebar and Agent Window views, possibly indicating state corruption that accumulates over multiple view switches.

Similar Agent Window bugs have been reported in other threads:

Replies from Cursor devs indicate that Agent Window is “in beta” and that a fix may be ready in the v1.8 update. However, 1.7.54 (the current “stable” version) has no indication that the Agent Window is in beta, and the UI element to open it looks like it’s just popping out the sidebar panel (not starting some entirely new experimental feature).

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

2

hi @dvg_p4 and thank you for the detailed bug report.

We are looking into the issue and I shared the post internally.