Sorry, I misspoke when I said nginx. Yes, it's Apache but that Apache config you show is not what is running because I see a DigiCert certificate. You can see for yourself using a site like this SSL Checker (link here)
Can you show output of
certbot certificates
Also, show this
apachectl -t -D DUMP_VHOSTS
As a note, below is not correct for any version of Apache. Versions prior to 2.4.8 use the ChainFile but then would be chain.pem and not fullchain.pem. See (this topic)