2D character falls through floor

I am using this script CharacterController2D/Assets/CharacterController2D/CharacterController2D.cs at master · prime31/CharacterController2D · GitHub
My player has a 2d box collider and ‘Is Trigger’ is unchecked. I have a tilemap that has a 2d Tilemap Collider. I also have a rigidbody 2d.
I used to use this script for the controller: 2D-Character-Controller/CharacterController2D.cs at master · Brackeys/2D-Character-Controller · GitHub
And this for my joystick: GitHub - hayzplayz/for-my-unity-question: yeah

My second question: Before i switched my controller script my player would constantly build up backwards momentum and they would go backwards. Occasionally just stop moving. Please help!

Hey! I solved my issue. I got the original codes and I made the mass on my rigidbody as low as possible. And I set everything else to default!