I.see not working with grabbers #45

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?