Hi. I have the same issue, but port 80 isn’t blocked. It was working fine, but then on Aug 17 it didn’t renew automatically. I have replaced the cacert.pem file like described here : LetsEncrypt certificate renewal failing and it does not work.
Here is the kind of messages I see in the logs, I have replace my actual domain name with www.example.com :
2021-10-28 00:26:55 -0400 08 mail WEBADMIN:0000000C: LetsE: Found current request
2021-10-28 00:26:56 -0400 08 mail WEBADMIN:0000000C: LetsE: Found current request
2021-10-28 00:26:56 -0400 08 mail WEBADMIN:0000000C: LetsE: Found current request
2021-10-28 00:26:59 -0400 08 mail JOBLOG:70000007: LetsE: Acme job executing
2021-10-28 00:26:59 -0400 08 mail JOBLOG:70000007: LetsE: AcmeChallengeState for www.example.com executing
2021-10-28 00:26:59 -0400 02 mail JOBLOG:70000007: LetsE: Acme challenge state failed, perhaps www.example.com cannot be accessed by the letsencrypt servers?
2021-10-28 00:26:59 -0400 02 mail JOBLOG:70000007: LetsE: Issuance Job for www.example.com abandoned!
2021-10-28 00:26:59 -0400 02 mail JOBLOG:70000007: LetsE: last protocol errType All OK!
2021-10-28 00:26:59 -0400 02 mail JOBLOG:70000007: LetsE: last protocol errDetail All OK!
2021-10-28 00:26:59 -0400 02 mail JOBLOG:70000007: LetsE: Job step action => Cannot complete current work item, abandoning
Any ideas? Thanks in advance