Why doesn’t screen mirroring support Facetime in landscape orientation?

I would like to use my smart tv to display Facetime from my iPhone 11 Pro. In the age of COVID-19, I don’t want my whole family huddled around a 5” screen to chat with friends and relatives. Additionally, I have a mount for my phone by the smart tv, so that viewers on the other end of Facetime can see my family comfortably sitting in my living room.

I am able to screen mirror via:

1) Airplay through AppleTV to my television; and

2) direct connection with my lightning-to-HDMI connector

HOWEVER, If I rotate my iPhone to display in landscape mode to fill my tv screen and provide a landscape display from my iPhone camera, the screen mirror does not rotate with iPhone when using Facetime. This appears to me to be a software glitch in the Facetime app. Most other apps on my iPhone project a landscape view in screen mirroring (via both Airplay and direct connection).

It seems as though this may be by design, that Apple does not want customers to use their large smart tv displays to Facetime.

Is there a workaround or other setting available to fix this condition? I suspect many people would choose to use such a feature while we’re all holed up in our homes for the next few weeks/months.