NPC falling through collider (floor) when moving

Hello guys! I'm new to game development in coregames. In fact i started today but in general I'm novice using unity.

I'm trying to do a game using the dungeon crawler template and the npc falls through the collider (floor) when it starts to move.

I have no idea how this can happend because the collider on the floor object is on, collider on the npc itself is on and it has an collider as a child that is on. I have checked and played around with all of these and i cant find the issue. The thing is that it starts to go through the floor when it starts to move, otherwise it is standing on the floor.

Does anyone know this issue?

Regards Daniel!