Sophos XG - Lets Encrypt broken - Certificate authority: Invalid or not installed

Hi, have you checked and followed this thread?

https://community.sophos.com/sophos-xg-firewall/f/discussions/130486/certificat-let-s-encrypt-untrust

Yes. No effect. I have removed the old CA certificates, added the new, re-uploaded my ssl certificate, but still no luck.

can you post a screenshot of the certificate and it's full chain (with chain details) without posting private details?

is this issue only on XG? are external hosts also reporting the certificate as invalid?

Also please post a screenshot of all your LE root certificates on your XG.

like:

Here are my screenshots. The certificate is here being served directly from my website on IIS - no problems. As soon as I enter from the outside where it has to pass through WAF in XG. It breaks.

The last screenshot is from my Certificate authorities in XG. The last of the R3 certificates holds the correct path.

Everything seems okay to me.

Here are my screenshots. The certificate is here being served directly from my website on IIS - no problems. As soon as I enter from the outside where it has to pass through WAF in XG. It breaks.

The last screenshot is from my Certificate authorities in XG. The last of the R3 certificates holds the correct path.

Everything seems okay to me.

looks OK.

do you have this on your XG?

it did not come pre-installed, we uploaded it.

I have the same issue, al the necessary intermediate and root authorities are installed, still the imported pfx lets encrypt certificates are marked with the red cross and the message "Certificate authority: Invalid or not installed Issuer

/C=US/O=Let's Encrypt/CN=R3.
This mentioned certificate is installed under Certificate authorities.
Also a waf protected website is reported by ssllabs supplying the old expired DST certificate, but 
that certificate is nowhere to be found (Certificate authorities) in the management interface of Sophos XG

SFVH (SFOS 18.5.1 MR-1-Build326)

I have both the X1 and X2. Pulled from Let's Encrypts website.