I've had 'Four Eyes' since it was introduced and its first year here I couldn't set a pod on it. The pollen was successful but I was soooo disappointed in not setting a pod.
I do grow in full sun, no shade of any kind and in zone 9b, the heat starts getting brutal early on.
This year the plant is a mighty clump and was receptive to nearly every dabbing attempt with other pattern pollen. It rejected my attempts at putting toothy pollens on it.
My deductions? This is one that needs full maturity to strut its stuff and can be persnickety in choosing its dancing partners.
Edit: Fresh pollen always in the early mornings - or just after a light rain at other times of the day. I don't do evenings.