Hello.

I'm trying to enter the correct tree, at night, after talking to Detective Someone with this specific team and it doesn't let me in. What's the issue?

 

What message are you getting when youre trying to enter the tree during night time?

That there's nothing but wild grass.

You interacted with the wrong tree then. The location is random for everyone and every night. Try to check everywhere in the ghoul swamp once its night time. Follow the child first and then find the detective in a random location next to a tree.

1 minute ago, Norex said:

You interacted with the wrong tree then. The location is random for everyone and every night. Try to check everywhere in the ghoul swamp once its night time. Follow the child first and then find the detective in a random location next to a tree.

Alright then, I'll do so and then eventually inform you.

1 hour ago, Norex said:

You interacted with the wrong tree then. The location is random for everyone and every night. Try to check everywhere in the ghoul swamp once its night time. Follow the child first and then find the detective in a random location next to a tree.

It appears I just had to reenter the forest.