test_start_tls_server_1() still fails randomly. Example on AppVeyor on my PR 5423:

https://ci.appveyor.com/project/python/cpython/build/3.7build11472

ERROR: test_start_tls_server_1 (test.test_asyncio.test_sslproto.SelectorStartTLSTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\projects\cpython\lib\test\test_asyncio\test_sslproto.py", line 293, in test_start_tls_server_1
    asyncio.wait_for(main(), loop=self.loop, timeout=10))
  File "C:\projects\cpython\lib\asyncio\base_events.py", line 564, in run_until_complete
    raise RuntimeError('Event loop stopped before Future completed.')
RuntimeError: Event loop stopped before Future completed.

I also had this failure on my Windows 10 VM when running "python -m test -R 3:3 -v test_asyncio". I skipped the test to be able to debug bpo-32710.