Some more things to check. Make sure that "Use random portraits" is enabled in settings. Check that the following path exists: "Strive/mods/randomportraits/info.txt". Unless you have changed the path to the "mods" folder in the mods menu from "user://mods/" to something else, it must be exactly that path. The game can apply the mod with a different path, but the mod cannot function with a different path.
Otherwise, post here the path of one of your images from the Strive folder to the file extension, so I can review that there isn't something wrong with the tags.