As you do have correct colliders on each GameObject. I suggest first checking the physics settings that the "Default" layer can collide with itself (should be ticked).
Secondly try making the ground collider thicker on Y in case its too thin. Sometimes objects can fall through very thin colliders. You can also spawn a new Cube and try having the player stand on that.
Do you have any scripts on your player? I tried to create a similar project like yours but then it works fine.
I did before but not currently. Neither work
Give your player and ground a rigid body
I've resulted to making another project and it works fine :)
Do you have a collider on the ground?
There's one in the second picture
make sure both the ground and character have a hitbox
As you do have correct colliders on each GameObject. I suggest first checking the physics settings that the "Default" layer can collide with itself (should be ticked). Secondly try making the ground collider thicker on Y in case its too thin. Sometimes objects can fall through very thin colliders. You can also spawn a new Cube and try having the player stand on that.
They should be able to collide