This appears to be resolved for me.
This has been happening to me as well. Firefox says something about the security certificate not being valid?
Additional info: this appears to only be occurring on my home internet connection, and I'm able to load the site fine on mobile data.
@jgs
I've been seeing this "NET::ERR_CERT_COMMON_NAME_INVALID" error since last night, on ChromeOS/Chrome 107.0.5304.92, and on Android 11/Firefox 106.1.0.