Hey, I get it. Losing work always hurts, especially if you spent a few hours in one chat.
This is a known intermittent UI bug with checkpoints. The Restore to checkpoint button sometimes disappears from view, and restarting Cursor brings it back. We’ve fixed similar regressions a few times, but the symptom keeps coming back sometimes. There’s no exact ETA for a fix right now.
A couple ways to recover work you already did if this still helps:
git reflog or git stash list if you made at least one commit or stash, you can often recover the state
In Cursor: Cmd+Shift+P > Local History: Find Entry to Restore. This is local file history and works separately from checkpoints
If you used an agent worktree, check the .cursor/ backup folder
To help the team finally catch the root cause, can you share if possible:
The Request ID for the message where the button disappeared Chat > menu in the top right > Copy Request ID
What was happening in the chat right before it vanished long thread, edit tool calls, switching models, canceling generation
Does it reproduce reliably or is it random
For the future as a safety net, commit more often, or at least run git stash before big agent sessions. Checkpoints are a convenience on top of git, not a replacement.