i installed letsencrypt from app center to give it a try. It ran successfully and created certificates for apache.
Wenn navigating to that domain using an up to date firefox i tan into a certificate issue:
Somehow ucs letsencrypt app used an outdated ca to create a certificate:
Let’s Encrypt Authority X3
Digital Signature Trust Co.
DST Root CA X3
valid to Wed, 17 Mar 2021 16:40:46 GMT
It is an updated version of ucs5. shouldn’t that app work out of the box?