I use a Twilio webhook to send SMS and mine is still working. However, there is an important difference between mine and yours.
In yours, you have all of the message parameters in the URL, which isn’t the way POST requests are usually made. Some web servers treat URL parameters the same as post body parameters, but some do not. There could have been a change in the Twilio backend that affects this, for example, but I do not know if that’s the case.
In any case, the recommended way to use it is to have the URL end with Messages.json.
Set the request type to POST, which you do have already.
Set the Request Format to Web Form. This is different than what you have set, I think.
Set the form fields appropriately. I set the To and Body from the event data, but you can hardcode those as needed if you prefer.
The authorization should be the same.