That would seem unlikely as my code is basically the same as your code and I’m not having an issue with WebHooks across three servers each with different combinations of topics, and callback URL’s
You could open up your server NGINX (assuming NGINX) access/error logs and check for the call from Twitch coming in and raising an error that doesn’t make it to node, or coming in on a route that your Node Express server isn’t binding a response on
If you have something like Cloudflare in front of your server that could be conflicting also