Turn off “This Connection Is Not Private” in Safari?

D. Hoffmann wrote:

When I connect to the web interface of the router on my local network via https, I every so often get the warning that, “This Connection Is Not Private.”

I do understand how to get past that and get to the router’s GUI.

However, in earlier versions of macOS it was possible to add the self-signed certificate of such sites to the Keychain Access app. Then I would never again be bothered about the fact that my router does not have a valid certificate. How is that done in macOS Sonoma?

What exact router...?

ref Your Connection Is Not Private - Apple Community

ref: “This connection is not private" Safari m… - Apple Community

today's standard is looking for HTTPS this is httpSecure... (read encrypted & secure communication)

the authentication of the accessed website and protection of the privacy and integrity of the exchanged data while it is in transit.

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS

This isn’t usually a certificate error.

The router firmware likely has latent http references embedded within its otherwise-https webpages.

It’s trying to secure the web management interface traffic, and is failing.

Check for router firmware updates, as a starting point.

As requested above, which router vendor and model?

Check for updates to those, and confirm that the https connections isn’t mixing in http connections.

This is unrelated to the use of a provate CA, and of having a privately-issued root CA profile loaded.

Your Router should be http:// not https://

I get them occasionally but I run blocklists via Brave and an app Little Snitch. I believe I even ran into one on Apples servers. It was https but only http.