Certificate Not Recognized

I am troubleshooting a certificate issue after a recent distro and NC upgrade. When I try to access my NCP admin panel, Firefox throws a certificate error, even though I have a certificate from Let’s Encrypt installed.

Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for :4443. The certificate is only valid for archlinux.

Error code: MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT

Any idea what might be wrong?

Here’s the background:

My ISP blocks ports 80 & 443, so I switched my NCP over to using ephemeral ports. This obviously breaks Let’s Encrypt client in NCP admin panel, so I used the manual DNS method (as described in https://docs.nextcloudpi.com/en/how-to-get-certificate-with-letsencrypt-using-dns-to-verify-domain/). Everything was working okay before the upgrade.

When I got the certificate error after the upgrade, I thought my certs may have been deleted, so I ran the DNS option again. It said the certificates were already in place, but I chose to have them reissued just to be on the safe side. But still no luck.