Unable to create a PDS with a member name specified. (as in example pipeline)

### Jenkins and plugins versions report

Environment

```text
Paste the output here
```

### What Operating System are you using (both controller, and any agents involved in the problem)?

Linux Jenkins installation accessing zOSMF on zOS 2.5.

### Reproduction steps

Run the example pipeline provided with the plugin.

### Expected Results

Should create a PDS with the new member "NEWMEM".

### Actual Results

Pipeline] step
Allocating dataset xxxxxxx.NEW.TEST3(NEWMEM) with connection: mvs3.cpa.state.tx.us:9000.
Dataset allocation failed. Reason: java.lang.Exception: HTTP code = 404; Message: Not Found
The `failOnExist` option is set to false. Continuing with execution.

### Anything else?

_No response_

### Are you interested in contributing a fix?

_No response_