current_time() returns different formats when frozen

[iboard]

The bug is

as you can see in this example, that the function current_time()
returns two different formats.
when it is frozen, it returns a NaiveDateTime where it returns
seconds since the epoche when unfrozen.

  test "use the default timer" do
    freeze_time(:default_timer, ~N[1964-08-31 06:00:00])
    :timer.sleep(1010)
    assert ~N[1964-08-31 06:00:00] == current_time() 
    unfreeze_time()
    assert current_time() > 1_000_000_000
   end

Expected behavior
The function should return seconds in any case.