Above 90 degrees, there is a blockage due to algorithms that are not adapted to counting the yield from panels turned to the north. At this point, it is not possible to position the panels this way. We are trying to fix this problem and we will try to improve it in the next update of the application.
Meanwhile, the solution could be to set the azimuth in the other direction, e.g. at -89 degrees - the yields will be minimum higher.