Who knows anything about fava beans? I’m thinking a lack of pollinators is the problem.
Ellendra! Your vast Bean knowledge is needed over here!
Fava beans, like most legumes, are automatically self-pollinating. It would be very surprising if the lack of pollinators was a problem.
Can I ask how you’re growing them? What, exactly, did they do that led you to suspect poor pollination? What time of year did you plant? What were the temperatures like during the time they flowered? Did other legumes nearby suffer the same problems?