Noob problem: Unable to manipulate object after adding MRTK scripts

Hey guys, I've been following microsoft tutorials on "HoloLens 2 fundamentals: develop mixed reality applications" more precisely in "Getting started with 3D object interaction": " https://docs.microsoft.com/en-us/learn/modules/get-started-with-object-interaction/5-7-exercise-manipulate-3d-objects-with-bounds-control " I have followed every step mentioned, when I added the "Object Manipulator", "NearInteractionGrabbable" and "Part Assembly Controller" scripts to my game objects and clicked on the Play button, I couldn't move any of the parts, I tried the righ click, space bar.. nothing works. I've had this problem before even in a very simple project including a cube, where after I click on the play button there's a sort of a cursor dot that if it's placed on the game object I'm able to manipulate it but once the dot is offsetted I can't manipulate it anymore. Can someone help me out in this problem? Thanks in advance.