You are not dumb, and how can you know why the character is standing on top of the water? If this is a plugin, then I suggest talking to the one who created the plugin.
It seems that the water still has collision enabled. Collision allows the character to not pass a surface or an area. You can disable collision on a mesh in your game. Simply select the mesh and in the details panel set the collision type to NoCollision.
I suggest looking at a few tutorials about collision if you want to learn more about it.
Thanks, this helped!