Bad design, most likely, and may be fixed in later production. This kind of thing is why it's not a great idea to buy a newly-designed vehicle early on.

Well tell your brother one thing, NEVER buy a first model year of a brand new or redesigned car. The issue is that the Bronco Sports are all made in Mexico which isn't exactly the best place for quality manufacturing. Maybe try going aftermarket with getting a good seat cushion that you can put on top, otherwise, there isn't much you can do.

Yes, I did warn him never to buy first or last years of car models but he likes new stuff. It's just an odd issue especially as the passenger seat is fine. No idea if it's a bronco sport issue across the board or maybe just something with the FE trim. The only thing I see different in the seats is the lumbar support for the drivers side. I have never had anything happen like that and I've had several cars with higher milage and yea the cushion wasn't as plush but to completely lose half the seat like is strange. Yes, I had heard that manufacturing was in Mexico that and of course the rear drivetrain recall which somehow he avoided. He may need an aftermarket cushion. Well he wanted new and exciting. Haha. I'll take my boring , reliable accord over his new disaster.