What does Issued by: R3 mean in Let's Encrypt certificates? Follow
When you create a Let's Encrypt on Section it now will be Issued by: R3.
R3 is the new intermediate certificate used by Let's Encrypt, as explained in the announcement from Let's Encrypt https://community.letsencrypt.org/t/beginning-issuance-from-r3/139018
If you check a site like SSLShopper you will see more information that shows the intermediate certificate and the full LE certificate.