Don't understand this asyncio error

Here's the code.

import asyncio
import aiohttp


async def fetch_numbers(session):
    counter = 0
    while True:
        counter += 1
        resp = await session.post("https://httpbin.org/post", json={"number": counter})
        yield await resp.json()


async def main():

    async with aiohttp.ClientSession() as session:
        counter = 0
        async for item in fetch_numbers(session):
            counter += 1
            print(item)
            if counter == 99:
                break

if __name__ == '__main__':
    asyncio.run(main())

Here's the error I get:

unhandled exception during asyncio.run() shutdown
task: <Task finished coro=<<async_generator_athrow without __name__>()> exception=RuntimeError("can't send non-None value to a just-started coroutine")>
RuntimeError: can't send non-None value to a just-started coroutine

I feel like this error shouldn't happen? I'm not sending anything using the generator. I'm open to any suggestions!