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.
This has been happening to me as well. Firefox says something about the security certificate not being valid?
This appears to be resolved for me.
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.