Ross Brawn “When the flap comes back, then the flow reattaches. We’re having some situations where the flap comes back and the flow doesn’t attach immediately – it takes a bit of time before the flow reattaches" “In Michael’s case in his qualifying lap there were several corners where the flow was unstable, and it happened in Nico’s case as well"
Oh i wouldn't expect them to make the same mistake twice.
So it's the flow then, either way i think they need to have the actuation in the middle.
Maybe the shark fin like surface on the actuator can help reattachment.
Otherwise, they need new wing profiles. It's not a problem a big manufacturer should be stumbling with.
edit: a quick fix as well is to notch the trailing edge of the centre of the flap and have a shorter chord length in the center cross-section. the flow would be easier to reattach.