Buggy collison bounderies

so im working on a project where i need collisions. I followd a tutorial on how to add them and they mostly work except for the fac that you can enter it from the top layer of pixels from the top left pictures. If anyone would like to help me the source code is here https://github.com/fuwwyUwU/platformer. The bug is probobly in the player class or collisonsprite class.

Since you already have a Rectangle class you can use Intersects:

if (CollisionBox.Intersects(sprite.CollisionBox))
   Do collision stuff

Hope this helps