Bug report: Unencrypted Data warning occurs on plex home page sign in, despite HTTPS URL

Attached is a screen shot of the problem. Navigating to PLEX.TV and pressing the SIGN IN button causes an error message warning that the login will send my password in unencrypted form. Has someone hijacked the plex site or its certificate or something? This is unsettling, especially considering that there was a prior leak of passwords from Plex in the past. The fact that I had to complete that same unsecure login just to report this bug is also unsettling. Anyone know what causes this?

See attached screen shot.