My trunk latch won’t work on my 2017 Hyundai Sonata. I hear it click but it won’t pop open. The back seat unlock is inside the trunk!

SOURCE: Trunk Latch Problem

You need to replace the Latch assembly part thats located inside the trunk

Thanks

SOURCE: 2006 Hyundai sonata trunk doesn't lock the hood

I had to reinstall the loose mounting hardware for the trunk upper latch.

SOURCE: Trunk wont open where is emergency switch inside trunk

I had the same problem as you. Take out the back seat and there is a large access hole to the interior. There are two bolts that are fairly easy to get to. Remove them and the truck latch is removed from the lid and trunk will open.

SOURCE: trunk/gas tank latch wont work (honda accord)

I have this problem now i got my trunk to lock by going in the trunk and removing the wire from the hook that was keeping it loose. Now i can lock my trunk but i am still looking for a way to get in my gas tank. Help me please if you can.

SOURCE: my trunk lid will not open on my 2005 nissan

Just beneath the latch ,you can see a clip,turn it up and close the trunk.Try opening it with the button near dash or remote.It should work.They designed it to avoid theft during vallet parking.The main key(steel one) is used only for ignition.There is another key(with a black rubber head) is for ignition and trunk.So if you want to avoid missing any items from trunk using vallet parking,use the main key,put the clip down and hand that to the person who is assisting you during vallet parking.