Downhill treadmill running showing as flat

I have a Wahoo Kickr Run treadmill. At the moment, the Zwift data files correctly show uphill gradients, but the downhill gradients (0% to -3%) just show as 0%. This is the same whether on auto or manual incline mode.

Please can Zwift implement correct downhill as well as uphill data for running? There is a big difference in effort when running at 0% and -3%. Showing -3% as 0% throws off all of the pace and speed data. This seems like it should be a simple fix. Thanks!