You've probably cracked a couple of the rear studs. This thread will give you a good idea of the internal construction and discusses what to do in even worse situations than yours. The problem is that the fin is mounted from INSIDE under the headliner.

https://www.kia-forums.com/threads/replace-shark-fin-cover.359302/?post_id=2106423#post-2106423

 

Mine is a 2017. I read that thread. Mine is intact, even the rubber gasket is still attached. Roof seems smooth, no screw holes I can see or feel under the back end that's lifted up to the middle of the fin. Should I just leave it? How hard can you press down without denting the roof. Also I have a full sun roof, so I'm not sure it's attached the same way.

 

If it appears intact, then I would just run a thin bead of silicone around the perimeter for a peace of mind.

 

It's about a quarter of an inch raised in the back, so a fair amount of silicone. That is my last line of attack if all else fails. I would prefer if I could get it flush again.

 

I believe you need to remove the head liner to access the hardware to fix it.. If you leave it the way it is. You will have water intrusion when it is raining out or if you wash your car.

 

I forgot to mention. My oldest daughter did the same exact thing to her 2020 Forte. But the damage was worse and required the entire roof skin to be replaced.. Because it was around the Covid period. She had to wait for the new roof skin to come from Korea, so she was without her car for nearly 5 months.

 

She had to wait for the new roof skin to come from Korea, so she was without her car for nearly 5 months.

Whatever for? A heavy duty zip-lock or similar stuck down to the roof over the antenna with occasionally replaced duct tape would have proved a lot more convenient in the end.