Blackmagic Playback of Unsupported Frame Sizes is 2K and not 1080p

Previously when in a 3840x2160 23.976 timeline I would set "Unsupported frame sizes: Scale Down". I'm intentionally using an HD only output card from Blackmagic (UltraStudio HD Mini) and not a 4K card so the 4K timeline will be an "Unsupported frame size" I'm using a Flanders DM240 external monitor. Using this method the output signal used to be 1080p and all was well. Now that signal is 2K which makes the image on the monitor appear slightly wider as the image is being squeezed from top to bottom. The PC version of PP does not do this and previous versions of Premiere did not do this, they output 1080p when set to Scale Down.

There is no other way to monitor a 4K or larger timeline on an HD monitor. As an online editor it is critical to see the proper aspect ratio on an external monitor even when scaling down.

MacBook Pro 16", M1 Max, 64GB Ram
Mac OS 12.3.1
Premiere Pro 22.3.1
BM Desktop Video 12.2.3