It is not possible to edit any optimization goals for ad sets that are in the Brand Awareness objective once those ad sets are created and Brand Awareness objective ads can now only be optimized for ad recall lift, where we serve your ads to maximize the number of people who will recall seeing an ad from your brand. You can see the FB article about this limitation by clicking here

In addition to that, Estimated Ad Recall Lift doesn't support manual bidding by design, so in Brand Awareness campaigns it's not possible to activate manual bidding, hence, Marvin bidding. 

Did this answer your question?