`await call_next(request)` gets stuck indefinitely on larger payloads

Question

I got this snippet from here.

When implemented, response = await call_next(request) gets stuck indefinitely when the JSON payload is too large.

What could be the reason? Is it the right way to modify the body of JSON in FastAPI?

class RequestContextLogMiddleware(BaseHTTPMiddleware):

    async def set_body(self, request: Request):
        receive_ = await request._receive()

        async def receive() -> Message:
            return receive_

        request._receive = receive

    async def dispatch(self, request: Request, call_next: RequestResponseEndpoint):
        await self.set_body(request)
        body = await request.body()
        jsonbody = await request.json()
        id_ = jsonbody['external_id']
        response = await call_next(request)    
        return response