I am having the same issue. I tested it with this file https://www.nexusmods.com/skyrimspecialedition/mods/12633/? I can download this file from the Europe 1 server, however the North American server has been kicking me to a 403 error. https://www.nexusmods.com/divinityoriginalsin2/mods/24/? This file does the same thing. Glad to see that I am not the only one with an issue.