why can't i asscess first element array input to simulink from workpace

hi ! i have question that can be essily but very hard to understand to me i have create model that using from workpace block to put array variable 'a' from simulink (a is array [1 2 3 4 5 6 ] as you can see , i have send you along with imagine matlab function that i write to assign fisrt element array a for element output but ,instead of scope display 1 it alway display 2 this is my this function

    % code
function element     = handle_vb( arr_anh) %%a is argument for arr_anh
element=arr_anh(1);

end very thank for help !!