Zoom Rooms App - Maintaining HD Resolution on Large Screen

[MediaFan]

When we start our Zoom Rooms app on a Mac mini connected to a large-format (maybe 90-inch) Samsung display, we notice that the MacOS dock gets much larger just before the Room Name, Sharing Key and time appear on the screen.  We think the Mac screen resolution is being downscaled, which results in lower-resolution profile pictures and less-than-1080 HD (we have that option on our account) resolution on our meetings and shared screens. Has anyone been able to force Zoom Rooms to keep the native high-resolutions that we seen when we are looking at the Mac desktop on the same screen?  Any ideas please?