According to the sign controller it is 168x96 not 1152x864 (I can see the pixels it most certainly is not 1152x864). Looks like the sign controller is set to scale to fill, which is why you are getting cropping.
Export a copy at 168x96 and it should play correctly.
I've run into specific digital signage systems that give you the odd pixel sizes.
Some I got away with doubling the actual number and their systems auto-filled and felt it was better looking that if I sent the actual 1:1 size.
Maybe its just in my head :)