No CAA record on cryptoblock.uk (wildcard=false) contains the issuance domain "letsencrypt.org". You must either add an additional record to include "letsencrypt.org" or remove every existing CAA record. A list of the CAA records are provided in the details.
cryptoblock.uk. 0 IN CAA 0 issue ""letsencrypt.org""
CAA records control authorization for certificate authorities to issue certificates for a domain
cryptoblock.uk. 0 IN CAA 0 issue ""letsencrypt.org""
A and AAAA records found for this domain
xsg.cryptoblock.uk. 0 IN A 149.202.74.156
The IANA public suffix is the TLD of the Registered Domain
The TLD for xsg.cryptoblock.uk is: uk
The current status.io status for Let's Encrypt
Operational