This was a recent change that we made directly in the BDF. I actually just blogged about this here -- FREE Xilinx Vitis 2019.2 Training for Ultra96-V2 (and update to the Ultra96-V2 BDF)
What GL Research found was that the Xilinx tools set the mirroring differently based on the version of Ubuntu that they were using. And Ubuntu 18.04 set it in such a way that it failed, which appears to be what you are finding. I'm not sure why the Ubuntu version causes that type of variability in the defaults from the Xilinx tools, but it can easily be corrected as you see in the latest Ultra96-V2 BDF.