Web Presenter 4K setup

Hi everyone,

I am in the process of setting up my Web Presenter 4K and am struggling with something. I have 3 x Ben Q 2700U 4K monitors in my workstation. The 3rd of these monitors is hooked up to my web presenter.

The way I'm doing it is there is an HDMI coming out of my Computer GPU, it passes through a BlackMagic HDMI to SDI 12G bidirectional converter, passes through the Web Presenter 4K, passes back through the bidirectional converter, than lands on the 3rd monitor. I thought because there is a 4K signal end to end here that everything would look good once it hits the monitor, but by default the Black Magic Web Presenter is sending a 1080p Signal to the monitor. If I change it to 4K all the icons get really tiny. Whereas the other two monitors by default scale correctly and show up in 4K.

I am waiting for some cables to arrive so I can test hitting the monitor FIRST then sending a DisplayPort OUT to the Web Presenter (won't know until Monday). But in the mean time can anyone think of a reason why this would be happening? There don't seem to be any settings on the Web Presenter that can change how it sends a pass through signal back out to my monitor.

See attached screen shot of each monitor DISPLAY settings.