[BUG] guess correct RawSources for sub-01/sub-01_T1w.surf.gii?

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Expected Behavior

_No response_

### Current Behavior

_No response_

### Error message

_No response_

### Environment

```markdown
- OS:
- Matlab:
- SPM:
```


### Branch

```markdown
- branch:
- version:
```


### Anything else?

_No response_