Certificate trust error dialog does not have enough information
On failing to connect due to certificate trust error, the problematic certificate is displayed, with options to cancel, reject, accept temporarily or accept permanently.
The fingerprint of the certificate is displayed, but what is needed in order to safely verify the cert is the issuer fingerprint, which is not available in this dialog.
In my case, the dialog gives the issuer as "DigiCert Cloud Services CA-1", but there is no way (from the information provided) to verify that this is the real DigiCert Cloud Services CA-1 certificate.
Adding the issuer fingerprint (and potentially the fingerprints of the whole chain) to the information displayed would make it possible to safely accept the certificate, if indeed it is safe to do so.