I have a backend developed using Quart that uses the quart_cors lib to avoid CORS problems. Everything was working fine, but when I try to add Application Insights from Microsoft Azure solutions the cors error returns.

This is the backend code:

app = cors(app, allow_origin="*", allow_headers=["Content-Type"])

Routes.py:

@app.before_request
    async def before_request():
        # Start tracing this request
        print("TEST")
        request.tracer = Tracer(exporter=AzureExporter(connection_string=os.getenv('CONNECTION_STRING_APPLICATION_INSIGHTS')), sampler=ProbabilitySampler(rate=1.0))
        request.tracer.span(name=request.path)

    @app.after_request
    async def after_request(response):
        # End tracing this request
        print("TEST 2")
        response.headers['Access-Control-Allow-Origin'] = '*'
        response.headers['Access-Control-Allow-Headers'] = 'Content-Type'
        response.headers['Access-Control-Allow-Methods'] = 'GET, POST, PUT, DELETE, OPTIONS'
        request.tracer.finish()
        
        return response

It returns like this on my react frontend application: