pytest-asyncio: pytest fails while using version asyncio-0.15.0

Python: 3.8 (docker image)

My pytest setup:

...
============================= test session starts ==============================
platform linux -- Python 3.8.9, pytest-6.2.3, py-1.10.0, pluggy-0.13.1 -- /builds/.../venv/bin/python3
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/builds/.../.hypothesis/examples')
rootdir: /builds/..., configfile: pytest.ini
plugins: hypothesis-6.9.2, asyncio-0.15.0
...

an error:

...
==================================== ERRORS ====================================
_____________________ ERROR at setup of test_async_ticker ______________________

fixturedef = <FixtureDef argname='event_loop' scope='function' baseid=''>
request = <SubRequest 'event_loop' for <Function test_async_ticker>>

    @pytest.hookimpl(hookwrapper=True)
    def pytest_fixture_setup(fixturedef, request):
        """Adjust the event loop policy when an event loop is produced."""
        if fixturedef.argname == "event_loop":
            outcome = yield
            loop = outcome.get_result()
            policy = asyncio.get_event_loop_policy()
>           old_loop = policy.get_event_loop()

venv/lib/python3.8/site-packages/pytest_asyncio/plugin.py:94: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <asyncio.unix_events._UnixDefaultEventLoopPolicy object at 0x7f07326b2bb0>

    def get_event_loop(self):
        """Get the event loop for the current context.
    
        Returns an instance of EventLoop or raises an exception.
        """
        if (self._local._loop is None and
                not self._local._set_called and
                isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())
    
        if self._local._loop is None:
>           raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)
E           RuntimeError: There is no current event loop in thread 'MainThread'.

/usr/local/lib/python3.8/asyncio/events.py:639: RuntimeError
...

The error appears when I run:

python -m pytest tests/test_dates.py::test_async_ticker -vv -duration=6  

where the test_async_ticker is:

import asyncio

import pytest

@pytest.mark.asyncio
async def test_async_ticker():
    async with dates.AsyncTicker() as ticker:
        await asyncio.sleep(0.001)

    assert ticker.time_elapsed().total_seconds() > 0

and AsyncTicker:

class AsyncTicker:
    '''Measures time between entering and exiting `async with` block.'''
    def __init__(self):
        self._start = None
        self._end = None

    async def __aenter__(self, *args, **kwargs):
        self._start = current_utc_instant()
        return self

    async def __aexit__(self, *args, **kwargs):
        self._end = current_utc_instant()

    def time_elapsed(self):
        return self._end - self._start