Tab Autocompletion Not Working Consistently (Cursor v2.4.21)

Support Bug Reports
1

Good evening,

I’m writing to report an issue with the tab autocompletion feature in the Cursor editor. Below is a detailed bug report following your requested template.

Where exactly does the error occur (in which feature/product)?

Cursor IDE

Describe the bug.
The code autocompletion feature using the Tab key in the editor is unstable. Suggestions have stopped appearing or appear very rarely. After restarting Cursor, the suggestion works exactly once, and then the feature stops functioning until the next restart. However, the IDE itself is accessible, and the AI chat works normally—the issue is specifically with the pop-up autocompletion suggestions (Tab autocompletion).

Steps to reproduce.

Open any project in Cursor IDE.

Start typing code (e.g., a variable or method name).

Wait for the pop-up autocompletion suggestion to appear.

Press Tab to confirm the selection—either the suggestion will not appear, or it will work only once after launching the program.

Expected behavior.
Contextual autocompletion suggestions should appear consistently while typing code, and pressing Tab should insert the selected option.

Operating System

Windows

Version Information

IDE: Cursor

Version: 2.4.21

Additional Information

The autocompletion option is enabled in the settings.

Troubleshooting steps already taken:

Disabled all extensions—the problem persisted.

Completely reinstalled the program—the problem persisted.

The issue occurs consistently and significantly hampers the workflow.

Could you please advise on how to resolve this? I am ready to provide any additional system or configuration details if required.

Thank you for your assistance.

Windows; Accepting suggestion via Tab doesn't work half the time
2

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

To help us investigate and fix this faster, could you edit your original post to include the details from the template below?

Bug Report Template - Click to expand

Where does the bug appear (feature/product)?

  • Cursor IDE
  • Cursor CLI
  • Background Agent (GitHub, Slack, Web, Linear)
  • BugBot
  • Somewhere else…

Describe the Bug
A clear and concise description of what the bug is.

Steps to Reproduce
How can you reproduce this bug? We have a much better chance at fixing issues if we can reproduce them!

  1. …
  2. …
  3. …

Expected Behavior
What is meant to happen here that isn’t working correctly?

Screenshots / Screen Recordings
If applicable, attach images or videos (.jpg, .png, .gif, .mp4, .mov)

Operating System

  • Windows 10/11
  • MacOS
  • Linux

Version Information

  • For Cursor IDE: Menu → About Cursor → Copy
  • For Cursor CLI: Run agent about in your terminal
IDE:
Version: 2.xx.x
VSCode Version: 1.105.1
Commit: ......

CLI:
CLI Version 2026.01.17-d239e66

For AI issues: which model did you use?
Model name (e.g., Sonnet 4, Tab…)

For AI issues: add Request ID with privacy disabled
Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
For Background Agent issues, also post the ID: bc-…

Additional Information
Add any other context about the problem here.

Does this stop you from using Cursor?

  • Yes - Cursor is unusable
  • Sometimes - I can sometimes use Cursor
  • No - Cursor works, but with this issue

The more details you provide, the easier it is for us to reproduce and fix the issue. Thanks!

4

Hey, thanks for the report.

I saw a similar case just yesterday. The user had the same issue where it works once after a restart, and they fixed it by disabling and re-enabling extensions: Code suggestions in the IDE stopped appearing (Tab completion)

Try this:

  1. Disable all extensions (Help > Extensions > three dots > Disable All Installed Extensions)
  2. Restart Cursor
  3. Check if Tab works
  4. Turn extensions back on and restart again

Also worth checking:

  • Cursor Settings > Network > Run Diagnostics. If there are network issues there, Tab may not work (chat uses a different protocol)
  • If you use a VPN or a corporate network, try disabling HTTP/2. In Settings, search for “HTTP/2” and enable “Disable HTTP/2”
  • Tab status in the bottom-right corner. Make sure it’s active

Let me know if the extensions workaround helps. If not, please share a screenshot of the Network Diagnostics results and your list of installed extensions, and we can dig deeper.

5

Thank you very much for your prompt and helpful response! Your suggestion truly solved the issue. The problem was fixed by switching the protocol in Cursor settings to HTTP/1.1. I’m not sure why it doesn’t work with HTTP/2 anymore, as it was functioning before. Thanks again for your excellent support!