[Bug]: Intermittent AgentState "stopped" in the backend

[enyst]

Is there an existing issue for the same bug?

• I have checked the troubleshooting document at https://docs.all-hands.dev/modules/usage/troubleshooting
• I have checked the existing issues.

Describe the bug

AgentState is an enum, and afaik it's supposed to have only those values in an AgentStateChangeAction / Observation, but recently I see a state change to "stopped", probably from here, and indeed it only happened when running with the UI.

This might be fine or just a matter of display in logs, or it may mean checks in the backend for AgentState.STOPPED don't trigger. Just recording this, because I may not remember all the unusual things. 😊

Current OpenHands version

[main](https://github.com/All-Hands-AI/OpenHands/commit/2a10ff13741dc47452240787b06def2463d38903)

Installation and Configuration

`make build`
`make run`

Model and Agent

Gemini
CodeActAgent

Operating System

Mac OS

Reproduction Steps

Run with UI for a while, and take a look at the console logs or check the event stream for "to stopped".

Logs, Errors, Screenshots, and Additional Context

No response