Error when renewing the certificate

Context:
Netlify instance: https://vbrb-0001.netlify.com/
Custom domain: https://planb.vanbreda.be

Problem
There is a problem renewing the certificate for our custom domain https://planb.vanbreda.be. It worked in the past, but now suddenly we receive the following error:

Error when renewing the certificate:
SniCertificate::CertificateInvalidError: Unable to verify challenge for planb.vanbreda.be

I’ve checked the following topics and docs:

What am I missing?

Kind regards,

Hi, @Ruben, and welcome to the Netlify community site. :+1:

I do see a CAA record for this domain when I test:

$ dig vanbreda.be CAA +noall +answer

; <<>> DiG 9.10.6 <<>> vanbreda.be CAA +noall +answer
;; global options: +cmd
vanbreda.be.		21599	IN	CAA	0 issue "globalsign.com"
vanbreda.be.		21599	IN	CAA	0 iodef "mailto:dnsadmin@inf.vanbreda.be"

This can also be confirmed here (at this time):

https://toolbox.googleapps.com/apps/dig/#CAA/vanbreda.be

Please add “letsencrypt.org” to the list there to allow the automatic Let’s Encrypt certificates to be provisioned for that site.

If there are other questions about this we are happy to answer.