Since we know that your certificate acquisition process works (I can already see the new certificate on crt.sh), we can safely straighten things out...
Please show the outputs of running these...
certbot delete online.cdiu.university-12-31-2020
certbot delete online.cdiu.university
certbot delete online.cdiu.university-0001
certbot delete online.cdiu.university-0002
certbot delete online.cdiu.university-0003
You won't lose anything of value by running those since you're using manual authentication and no installer.