Issue with CORS error when fetching data from Sanity Studio in React App

Hello everyone,I have deployed my first React App on Netlify, and everything apart from the sanity blog I’ve created works.
When I check the console I get the following error message, what have I missed?

Hey User! Are you still having this issue? If so, is this error occurring in your studio or your frontend?

Yeah, unfortunately.I get this error in the front-end on my live published website.

I have added my url to the CORS origins, but still nothing
😞

When trying this in developer mode, everything works like a charm, when deployed the .env variables works, bit I can’t seem to find anything about

networkError

, so I wonder if Sanity Studio block the URL somewhere.
Have you heard about this before or do you have any clue how this can be resolved?

When trying this in developer mode, everything works like a charm, when deployed the .env variables works, bit I can’t seem to find anything about

networkError

, so I wonder if Sanity Studio block the URL somewhere.
Have you heard about this before or do you have any clue how this can be resolved?

I found this, but I’m not sure this is related: https://www.sanity.io/answers/network-error-while-attempting-to-reach-https-p1602312290146900

Which browser are you using and do you have any enhanced privacy settings?

Google Chrome, but I can re-create this in Firefox

And also Safari

So for some reason it won’t fetch the data, caused of this “Network Error” 😞

I just realized that the firefox browser shows additional info:

I did some research and found this “Basically this errors are due to restriction a browser applies while loading the resources from other site. Let says your site X is trying to load resources like js/css from Site Y, A policy on browser gets triggered and blocks the resources if site Y doesn’t allow other site to request content. This action causes above error message to show up in the console window.
To fix this issue, Site Y has to send Access-Control-Allow-Origin: * response header to allow other site to load resources. In case you want to allow only site X, then site Y should send Access-Control-Allow-Origin: http://<domain-of-site-x>> to browswer.” (from
https://community.akamai.com/customers/s/article/Cross-Origin-Request-Blocked-The-Same-Origin-Policy-disallows-reading-the-remote-resource-at-URL?language=en_US#:~:text=You%20may%20have%20observed%20%22Cross,the%20resources%20from%20other%20site . ), but I feel a bit confused where this needs to be allowed.
I might be on the wrong track, but I’d rather share then not.

Sorry for spamming, but I found this:
https://www.sanity.io/docs/cors
And I tried around some stuff with the
CORS origins, and I came to the conclusion it works when I added my url like

<https://www.domain.com>

instead of

<https://domain.com>

it worked.

I did the mistake of thinking that would be added in the background but I got it working! 😄