**Affected version:** 8.2 - 8.5.2
**Fixed in:** 8.5.3

### Problem Description

The problem applies to transforms that use more than 1 CCS cluster or 1 local and 1 CCS as source. A typical source could look like this (the important part: `remotes*`):

```
        "index" : [
          "remotes*:filebeat*"
        ],

```

If 2 indices share the same name the transform might fail with an error similar to this:

```
 Failed to retrieve checkpoint due to: Duplicate key logs-2022-11-14 (attempted merging values [... and ...]
```

Similar to the above the `_stats` call is broken for such a transform, it can fail with an error message starting with:

```
Failure during checkpoint retrieval
```

This can happen even if the transform is in state `STOPPED` or `FAILED`.

### Mitigation

Choose _one_ of the following mitigations:

 - split your transforms to use max 1 CCS/local indices

_or_

 - avoid upgrading to 8.2, until the issue got resolved (this is a regression of #80984)

_or_

 - avoid duplicate names for your indices even on remote cluster, e.g. name the index: `remote1-filebeat...`, `remote2-filebeat...`


### Solution

This is a regression of #80984 which introduced a new way of check-pointing. The remote needs to be prefixed to the index name.
x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/checkpoint/DefaultCheckpointProvider.java
);
            }
        } catch (Exception e) {
            listener.onFailure(e);
        }
    }
    private void getCheckpointsFromOneCluster(
        Client client,
        Map<String, String> headers,
        String[] indices,
        String cluster,
        ActionListener<Map<String, long[]>> listener
    ) {
        if (fallbackToBWC.contains(cluster)) {
            getCheckpointsFromOneClusterBWC(client, headers, indices, cluster, listener);
        } else {
            getCheckpointsFromOneClusterV2(client, headers, indices, cluster, ActionListener.wrap(response -> {
                logger.debug(
                    "[{}] Successfully retrieved checkpoints from cluster [{}] using transform checkpoint API",
                    transformConfig.getId(),
                    cluster
                );
                listener.onResponse(response);
            }, e -> {
                Throwable unwrappedException = ExceptionsHelper.unwrapCause(e);
                if (unwrappedException instanceof ActionNotFoundTransportException) {
                    
                    logger.debug(
                        "[{}] Cluster [{}] does not support transform checkpoint API, falling back to legacy checkpointing",
                        transformConfig.getId(),