Too many certificates already issued for exact set of domains

Hi @xtrgeo

do you really use Certbot, if you have an ISPConfig? That's bad, Ispconfig has an integrated solution you should use.

Check

How did you create these 5 certificates?

CertSpotter-Id Issuer not before not after Domain names LE-Duplicate next LE
986411114 CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US 2019-06-25 20:45:05 2019-09-23 20:45:05 onlinebooking.lifefitnesscenter.gr - 1 entries duplicate nr. 5 next Letsencrypt certificate: 2019-07-02 18:35:06
986375555 CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US 2019-06-25 20:11:10 2019-09-23 20:11:10 onlinebooking.lifefitnesscenter.gr - 1 entries duplicate nr. 4
986335162 CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US 2019-06-25 19:31:04 2019-09-23 19:31:04 onlinebooking.lifefitnesscenter.gr - 1 entries duplicate nr. 3
986320794 CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US 2019-06-25 19:17:04 2019-09-23 19:17:04 onlinebooking.lifefitnesscenter.gr - 1 entries duplicate nr. 2
986271905 CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US 2019-06-25 18:35:06 2019-09-23 18:35:06 onlinebooking.lifefitnesscenter.gr - 1 entries duplicate nr. 1

Manual with Certbot?

If yes, what says

certbot certificates

You should see the 5 certificates, so import one with your ISPConfig.