I operate in French. For the May Watchtower studies, I need to import the French March Watchtower. I got 0 meetings imported. I then imported the March English Watchtower; 5 meetings imported in English. I then went to a June meeting and clicked on the Import WT… link. Here I selected the March French Watchtower. The 5 May study articles were imported in French, replacing the previously imported English study articles.
This worked for all the following months as well.