R3 SSL Certificate Expired

[wackyblackie]

You need to install the latest Let’s Encrypt root certificate:

Chain of Trust - Let's Encrypt

Certificate Not Trusted By Device

Recently, the DST Root CA X3 expired and thus some caused trouble. However, all certificates now should be using the ISRG Root X1. Try clicking the “Certificate Information” and look for DST Root CA X3. You can read more here: EDIT: Your site is working fine for me.