random_case(random_name) - Why won't the method to retrieve random data work?

I have written the following code to retrieve "Random Case" and "Random name". All forum advice is to use the code as set out in the last "random_both" method. The aim is to return Random names "Ollie" and "Ana" either random(upcase / downcase). The code prints the right answer to the console but doesn't pass all the required tests? Why?

'''

name = "Jordan"

def upper(string)
  string.upcase
end

def lower(string)
  string.downcase
end

def random_name
  ["Ollie", "Ana"].sample
end

def random_case(string)
  [upper(string), lower(string)].sample
end

def random_both(string)

random_case(random_name) 

end
'''

Other methods I attempted that returned JORDAN instead of "Ollie , Ana" are :

'''

def random_both(string)
puts mixm = [random_name + random_case] 
end

'''

'''

def random_both(string)
 mixm = Proc.new{  
  y =  [upper(string), lower(string)].sample
  j = ["Ollie", "Ana"].sample
  k = [y, j].sample
 }

end

mixm.call

'''

What other simpler solutions could work?

Thank you!