> AssertionError: timing 608.0 ms seconds > max timing 500.0 ms seconds;
> the clock 'monotonic' has a resolution of 15.6 ms;
> tolerate 1.0 ms seconds

Is it a virtual machine or a physical machine? Was your Windows busy? Did you run tests in parallel?

Only tolerate a difference of 1.0 ms is maybe too aggressive. A default of 100 ms is maybe more realistic?

Currently, this specific test accepts a difference of 500 ms:

         # Issue #20101: On some Windows machines, dt may be slightly low
-        self.assertTrue(0.45 <= dt <= 1.0, dt)
+        support.check_time_delta(0.5, dt, 0.5, clock='monotonic')