and that is the certificate used right now when you try to access to icemaps.com but the certificate used right now by synodins.com is the one issued at 21st May that only covers 2 domains synodins.com and www.synodins.com.
So, you need to configure your synodins.com VirtualHost to point to the same certificate used for icemaps.com.
That is not supposed to happen when you just renew your existing certificates.
Which parts of the directions you linked to did you follow for the renewal? All, from the top? Or just from “Automating renewal” and downwards? Because this new certificate including all the domains suggests you started “over”.
How to fix this? I’m not sure if certbot can fix this, but you might want to look at the location of the new certificate in /etc/letsencrypt/ and check if the VirtualHost sections of your Apache configuration are pointing to the right certificate location.
I don't use Ubuntu but the conf files for your Apache should be here /etc/apache2/sites-enabled/ so you need to edit the conf file for synodins.com and modify SSLCertificateFile and SSLCertificateKeyFile directives to point to the same files as you are using for icemaps.com.
I’m glad you got it working but it is really strange because icemaps.com and synodins.com are using different certificates but as you said, in your Apache conf both points to the same certificate so you should have some other virtualhost or conf for icemaps.com, I think you should recheck the conf.
So, icemaps.com is using this path /etc/letsencrypt/live/synodins.com/ for the certs and synodins.com is using this one /etc/letsencrypt/live/synodins.com-0001/ but you said that your web server conf files for both domains point to /etc/letsencrypt/live/synodins.com/ which seems it is not true, synodins.com conf file must be using /etc/letsencrypt/live/synodins.com-0001/ if it is not there is in some conf file.
There is no problem at all if you know what you are doing.