Your DNS for www.deepthought.com.au is correctly configured and verified, but the certificate has hit a Let's Encrypt rate limit, which typically happens when a domain is removed and re-added too many times (the limit is 5 duplicate certificates per domain per week). This rate limit is enforced by Let's Encrypt, not by us, so we are unable to reset it. You will need to wait 7 days from when the limit was hit before a new certificate can be issued, and in the meantime, please avoid removing and re-adding the domain as that will reset the waiting period.

Seems www.deepthought.com.au has now been connected securely despite the Railway settings showing:

Failed to issue TLS certificate

Let's Encrypt rate limit reached. Please wait before retrying.

This error cannot be automatically retried. Please check your DNS configuration or contact support.

Your DNS is correctly configured and verified, but our system still shows the certificate in a failed state due to the Let's Encrypt rate limit. The HTTPS connection you're seeing in your browser is likely being served by a previously issued certificate that hasn't expired yet. The dashboard error should resolve on its own once the rate limit window (7 days from when it was hit) passes and a new certificate is successfully issued - just avoid removing and re-adding the domain in the meantime.

"The HTTPS connection you're seeing in your browser is likely being served by a previously issued certificate that hasn't expired yet", which means technically it is all good?

Yes, as long as HTTPS is loading correctly in your browser, your site is functional for now. The dashboard error will persist until the rate limit window passes and a new certificate is issued, but your existing certificate is still serving traffic. Just avoid removing and re-adding the domain so the rate limit clock isn't reset.