My WEBGL game is encountering issues with CORS but not other games?

That's not enough information. Where is your game hosted? Most likely not on the same server you are trying to connect to, right? In that case the server you try to connect to has to explicitly allow access from a foreign domain. This is a security measure of browsers. A website is not allowed to load resources from foreign domains unless that server allows such requests. There is nothing you can do about that besidse: Hosting your game and whatever backend service you try to access on the same server, or make sure the backend server allows access from your other domain. You can not break out of the security sandbox of the browser, you have to be let out.