Placket of chore coat not laying flat after wash

I have a linen chore coat and when I first bought it, the front part of the jacket where the buttons go (the placket?) lay down flat like you'd expect but after chucking it in the wash (on cold) and hang drying it, the placket never seems to actually stay down. It just splays outward and it looks pretty dumb IMO (see picture). I've tried ironing it down flat but no luck. Is there anything I can do to get it back to when it was new? I'll even take it to a tailor or something but no idea what they'd be able to do. Thanks!