Server not using Let's Encrypt cert

[cja-usask]

I've set up a Let's Encrypt cert for my proxmox host. If I go into the ACME section and look at the account, it says my account is Valid. But it doesn't look like the system is using the new certs. Is there something I need to do for them to kick in? I thought they would automatically.

If not, is there a good log location for me to review for errors with this process?

Thanks.