Hi! Make sure you have collision group set to character for the character and physics set to dynamic. Also for the platform make sure to have collision group set to platform and physics set to static. I would suggest you to start from a template or follow tutorials on YouTube. Have a good day!
jump node works only with Dynamic objects so when you add jump node, the object auto changed to dynamic so he drops out make this path as static object and affected asset character or all and change character physics from static to dynamic
