I.see not working with grabbers

Hello, 
 I have not being able to make this simple example work:

Scenario('First Scenario', function\* (I) {
    let grabberResult = yield I.grabValueFrom('input[name=firstName]');
    I.see('XKJSHJDSJXHJSKHXS');
});

The grabber works fine, then problem is the I.see('XKJSHJDSJXHJSKHXS'); even though there is no text
'XKJSHJDSJXHJSKHXS' it still passes OK. 

Is this a bug?   
