Try to remove it from Railway and remove the CNAME from your DNS configuration, wait a bit, then add it back

I've tried that. Deleted from Railway and from Squarespace, then put it back 12 hours later. Still not working.

Anything else I could do?

Squarespace does not support root level CNAMEs, you will need to use Cloudflare's nameservers.

https://developers.cloudflare.com/dns/zone-setups/full-setup/setup/

Hey Brody, I'm not using a root level CNMAE: https://www.leticiagoncalves.dev/

Good callout, either way, there is no CNAME on that domain you used -

https://www.nslookup.io/domains/www.leticiagoncalves.dev/dns-records/#google

(We use Google's DNS servers to check domains)

Hello,
Project ID: 60d73e41-7abe-4350-85cb-32205ec70e33
I have been trying to connect my custom domain but as long as I setup dns and cname records it ends up not working. And giving 404 error as a response. Screenshot bellow.

Your custom domain seems to work fine? - https://www.leticiagoncalves.dev/

Can you tell me the issues you are facing with it?

Please note that the random CNAME that was given is not meant to be accessed directly, so if that's what you are doing then seeing a 404 for that is normal.

That's not my custom domain.

Yes it is, that is the custom domain attached to the service you linked when creating this thread.

It's also the domain you wrote in your original message.

Now I see that I posted into someone else’s thread. My custom domain is vandettagroup.net

Project ID: 60d73e41-7abe-4350-85cb-32205ec70e33

Well also my bad for not realizing lol.

I see that OP's domain works fine, and you have your own thread now, so going to mark this as solved.