I've never experienced that on my 2013 12 & 9m Wave, 2015 7m Wave kites. I weigh 95kgs(ish)
I have experienced it on a 8m 2012 Varial X, when I had pulled in all the depower on the cleat. The kite had tipped so far forward, the wind got on top of the canopy. Not a nice experience. It was blowing high 30's into 40's
I've flown my 9 in similar winds and my 7 in more than that (40+). No problems. I love the 7

I always pump up as hard as I can, i.e. can I fold the LE when it's hard to pump any more in. If not, then it's hard enough.
I also have an electric pump, that is set to 8psi and I don't have issues when it's pumped by that.
Have you checked your line lengths? They could contribute to some issues with them. Are you using the Airush bar?