"why does this happen?"
Because local functions are only callable within the same file. This is explained in the documentation: "In a function file, the first function in the file is called the main function. This function is visible to functions in other files, or you can call it from the command line. Additional functions within the file are called local functions, and they can occur in any order after the main function. Local functions are only visible to other functions in the same file."
If you want to call both functions outside of that file then by far the easiest way to achieve that is to write each function in its own file. If you really really need to call a local function outside of its own file then create a handle to it and pass that handle as an output argument (I have only rarely seen use cases where this is required).
