how do i fix this?

tikiserto

Hello, so i have this problem where following the "2d movement in unity" video from 2018, where when i added everything to make the character be able to crouch when i start testing the game the box collider just activates and de-activates, if someone has any idea what can be just say it, i will be trying anything cause i been trying to fix this quite a while now, please and thanks.