uvicorn and fastAPI with pyinstaller problem when uvicorn workers>1

I had checked PyInstaller and FastAPI (maximum recursion depth exceeded) and Pyinstaller-compiled Uvicorn server does not start correctly

FastAPI demo main.py:

import uvicorn
from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def root():
    return {"hello": "world"}

if __name__ == '__main__':
    uvicorn.run(app, host="0.0.0.0", port=58000, reload=False)

Run pyinstaller first pyinstaller -F main.py --clean and add hidden_imports in spec:

hidden_imports=[
                'uvicorn.logging',
                'uvicorn.loops',
                'uvicorn.loops.auto',
                'uvicorn.protocols',
                'uvicorn.protocols.http',
                'uvicorn.protocols.http.auto',
                'uvicorn.protocols.websockets',
                'uvicorn.protocols.websockets.auto',
                'uvicorn.lifespan',
                'uvicorn.lifespan.on',
            ]

It works good, but the app must be string when workers greater than 1:

WARNING: You must pass the application as an import string to enable 'reload' or 'workers'.

So I change to:

if __name__ == '__main__':
    uvicorn.run("main:app", host="0.0.0.0", port=58000, reload=False, workers=2)

After doing that, I ran the app dist/main and it created many apps like below, using 100% CPUs and 100% memories rapidly:

error message

Works on Python 3.8.3 and pyinstaller 4.0

from uvicorn and fastAPI with pyinstaller problem when uvicorn workers>1