SSL Issues: Certificate has expired

I pinged their support and got this:

I am sorry to hear that you are having issues at your end. We are aware of intermittent issues in our edge presenting expire certificates. This issue is only affecting a small percentage of our customers using Let’s Encrypt.

We’ve changed the issuing CA to DigiCert, as this will resolve this issue.

So not sure if they are doing it more broadly or in reaction to my ticket.