Yes, I had the exact same problem with the first 800D I bought. The power button wouldn't pop back unless I wiggled it or pressed the panel around it.
I made a thread about it a 2-3 weeks ago, and someone suggested that I could connect the reset button to the mainboard power button connector, which would work in a pinch, but I didn't want to settle with that on a premium priced case.
I returned the case to the store as faulty, and got another one.
I have to say, I also had a P64 SSD that commited suicide after only half an hour of uptime, so my impression of Corsair being quality has unfortunately sunk considerably.