Investigate Python 3.8 windows test failure

[xrmx]

This was from unrelated code change:

_____________________________ test_interval_timer _____________________________

    def test_interval_timer():
        func = mock.Mock()
        timer = IntervalTimer(function=func, interval=0.1, args=(1,), kwargs={"a": "b"})
        timer.start()
        time.sleep(0.25)
        try:
>           assert func.call_count == 2
E           AssertionError: assert 1 == 2
E            +  where 1 = <Mock id='2848397612848'>.call_count

tests\utils\threading_tests.py:46: AssertionError