Your wildcard certificate is failing because your DNS provider is serving stale, cached ACME challenge values instead of letting the certificate authority follow the CNAME delegation to read the current token. This makes every issuance attempt fail identically, even though your DNS records look correct from a normal lookup. To fix this, delete the ACME challenge CNAME record at your DNS provider, wait a minute or two, then recreate it using the same value shown in your Railway dashboard for that domain.

I did everything in the answer but still getting Failed to issue TLS certificate

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An internal error occurred. Please retry or contact support. , I almost delete both domains, all the CNAME, TXT, Everything, keep 1 hour between the creation of new ones and still the same response

The underlying problem is still present: your DNS provider (Cloudflare) is still serving two stale ACME challenge TXT values from earlier issuance attempts, even after you deleted and recreated the record. Deleting the CNAME does not clear Cloudflare's internal cache of the flattened TXT values it previously resolved, so the certificate authority keeps reading tokens we never published and rejects the challenge. You will need to contact Cloudflare support and ask them to purge the cached TXT records at the ACME challenge subdomain for your zone, since that cache is on their side and not something you or we can clear through DNS record changes alone.