You can also ease the outhaul so the bottom of the sail has a slightly rounded curvature. Try easing the cunningham and halyard. As you make each new adjustment to the sail, wait a moment to feel its effect. And ask the driver how the boat feels after the adjustment. Also, any time you make an adjustment, do it as smoothly as possible.
Abrupt changes can shake any existing flow off the sail and that exacerbates the situation.
But only one letter per subject, so give it your best shot and don't whine if people disagree. As a principal race officer for various regattas on Lake Ontario, I am horrified by the tales of boats damaged and then gone-missing, as told in the last two issues of the 'Butt. I routinely instruct all race personnel to keep a physical count of all the boats on the course. In big fleets that's hard, especially in heavy seas. And while this is sometimes challenging, it is vital.