I have a recurring problem where setting a layer's CRS sends the layer to the same incorrect location. WGS84 sends the layer to the ocean south of West Africa. British National Grid sends the layer to the ocean off the coast of Cornwall. It's done this with multiple layers including one I georeferenced myself (If I upload that layer it goes to the correct location automatically but adding a CRS will once again send it to one of the two wrong locations I just mentioned).
This must be a user error of mine to be producing the same results so consistently. Has anyone had this same thing happen? What am I doing wrong?