Why such an exception: ConnectionResetError?

Question

Django

I did a task manager on Django, everything works fine, but when I exit the browser on both the computer and the phone, an exception is displayed in the console:
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host

Full text of the error

Exception occurred during processing of request from ('192.168.1.101', 55129)
Traceback (most recent call last):
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\socketserver.py", line 650, in process_request_thread
self.finish_request(request, client_address)
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\socketserver.py", line 360, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\socketserver.py", line 720, in __init__
self.handle()
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\servers\basehttp.py", line 174, in handle
self.handle_one_request()
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\servers\basehttp.py", line 182, in handle_one_request
self.raw_requestline = self.rfile.readline(65537)
File "C:\Users\Нодир\AppData\Local\Programs\Python\Python39\lib\socket.py", line 704, in readinto
return self._sock.recv_into(b)
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host
----------------------------------------

Isn't it bad? But at the same time, the application continues to work without problems.

Link to github