When does a sequence ends ? My algorithm finds max until same number is generated second time.
I pass 20 tests and then fails due my maximum is smaller than expected. Could someone please explain me when method should return maximum value :)

expected:<615043> but was:<1230086>

Test cases in Python would be better if they were factorized to avoid repetitions. It's easy to create a generic function dotest that does the job for all tests, fixed and random. That would lighten the tests page and would be much more readable. Something like:

def dotest(n, expected):
  actual = user_function(inputs)
  test.assert_equals(actual, expected, f"Test failed with n = {n}")
  
  # then just do in the tests:
  dotest(n, expected)

You should add in description that this procedure always generates a cycle.