PyQt webbrowser become a virus

I'm trying to combine backend and frontend.

I've created a frontend using PyQt webbrowser:

from PySide2.QtCore import *from PySide2.QtWidgets import *from PySide2.QtGui import *from PySide2.QtWebEngineWidgets import *import sysclass MainWindow(QMainWindow):    def __init__(self, *args, **kwargs):        super(MainWindow, self).__init__(*args, **kwargs)        self.browser = QWebEngineView()        self.browser.setBaseSize(800, 600)        self.browser.setUrl(QUrl("http://127.0.0.1:8000/"))        self.setCentralWidget(self.browser)        self.show()def gui_main():    app = QApplication(sys.argv)    window = MainWindow()    app.exec_()if __name__ == "__main__":    gui_main()

The backend is using fastapi:

from typing import Unionfrom fastapi import FastAPIapp = FastAPI()@app.get("/")def read_root():    return {"Hello": "World"}@app.get("/items/{item_id}")def read_item(item_id: int, q: Union[str, None] = None):    return {"item_id": item_id, "q": q}def backend():    import uvicorn    uvicorn.run(app)

So far, everything is good. I can launch backend and start debugging:uvicorn backend:app

But when I tried to create a single executable using pyinstaller:pyinstaller --onefile main.py

The main.py just launches backend and frontend:

from backend import backendfrom gui import gui_mainimport multiprocessingif __name__ == "__main__":    p = multiprocessing.Process(target=backend)    p.start()    gui_main()

The resulting app keep poping up windows and exausted all memory.

I've tried to restart computer, but the issue remains the same.