Adobe CC 2014 uses a new video output pipine called Mercury Transmit that, in theory at least, works in similar fashion as video output does from Premier Pro.
I think the scaling feature you're talking about is something AE did internally before sending its image to the video output interface in previous version. Now the native image is sent thus the video hardware it self has to deal with any scaling or cropping required. I beilive the device you're talking about can't handle up or downscale.
I could be wrong but from the sounds of it this is what's happening. I would also argue if the above is the case it would be lovely for Adobe to add a "scale and crop" feature back as video hardware tends to be fussy about legal comp sizes.
The up-side of the new model is supposedly better perfromance and a true 10-bit output pipeline.