No CAA record on resolver-ip.dynamic.estada.ch (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.
resolver-ip.dynamic.estada.ch. 0 IN CAA 0 issue ";"
Some DNS records were found that indicate TXT records may have been incorrectly manually entered into DNS editor interfaces. The correct way to enter these records is to either remove the domain from the label (so enter "_acme-challenge.www.example.org" as "_acme-challenge.www") or include a period (.) at the end of the label (enter "_acme-challenge.example.org.").
The following probably-erroneous TXT records were found:
_acme-challenge.resolver-ip.dynamic.estada.ch.resolver-ip.dynamic.estada.ch. 0 IN TXT "22"