openclaw - 💡(How to fix) Fix [Bug]: Browser tool cannot connect to self-hosted Browserless remote CDP in Docker even though /json/version?token=... succeeds

"browser": {
  "enabled": true,
  "defaultProfile": "remote",
  "profiles": {
    "remote": {
      "cdpUrl": "ws://browserless:3000/?token=xxxx"
    }
  }
}

### Steps to reproduce


### Steps to reproduce

```md
1. Run OpenClaw gateway and Browserless on the same Docker Compose network.
2. Configure a browser profile with:
   `ws://browserless:3000/?token=xxxx`
3. Trigger a browser action such as a `navigate` call.
4. Observe browser tool failure.

### Expected behavior

OpenClaw should establish a remote CDP connection to Browserless and navigate normally.

### Actual behavior

OpenClaw reports:

`browser failed: Remote CDP for profile "remote" is not reachable at ws://browserless:3000/?token=xxxx`

### OpenClaw version

2026.4.15

### Operating system

Synology Linux

### Install method

docker

### Model

qwen/qwen3.6-35b-a3b

### Provider / routing chain

openclaw->lm studio

### Additional provider/model setup details

This does not look like a basic DNS/port/container problem:

- Browserless is reachable from the gateway container
- token auth works for `/json/version?token=...`
- but the CDP websocket handshake never becomes a live session

This appears to be a remote CDP websocket handshake/compatibility issue between OpenClaw's browser service and self-hosted Browserless in Docker.

### Logs, screenshots, and evidence

```shell