There's also an incident reported on BugZilla that's related to this: 2072647 - Sectigo: Violation of TLS BR 7.1.3.2.2 in OCSP responses
I have received a couple of responses from Sectgo and provided them additional information. I will provide an update once they provide me one.
Hello, just checking in to see if Sectigo got back to you with a timeline or update.
I heard back from a contact on Sectigos T3 Team, and they reported the OCSP issue related to the NULL parameter has been fixed.
I just tested with the 5.8.0 certbot snap install and it seems to be working correctly now without the error hitting.
certbot certificates -vvv
Root logging level set at 0
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Starting new HTTP connection (1): ocsp.sectigo.com:80
http://ocsp.sectigo.com:80 "POST / HTTP/1.1" 200 279
OCSP response for certificate /etc/letsencrypt/live/[redacted]/cert.pem is signed by the certificate's issuer.
OCSP certificate status for /etc/letsencrypt/live/[redacted]/cert.pem is: OCSPCertStatus.GOOD
Notifying user: Found the following certs:
Certificate Name: [redacted]
Serial Number: [redacted]
Key Type: ECDSA
Identifiers: [redacted]
Expiry Date: 2026-11-22 23:59:59+00:00 (VALID: 47 days)
Certificate Path: /etc/letsencrypt/live/[redacted]/fullchain.pem
Private Key Path: /etc/letsencrypt/live/[redacted]/privkey.pem