I found this bug long time ago, it's not one of those game breaking glithes, but i think it should be fixed in future.
Maybe this is a well known bug, but i didn't find a thread about it.
Ok, among all soldier classes in the game, the "Rifleman" concidered as a basic one. All new hired soldiers arrive with this class.
But, if i decided to change the "Rifleman" class name to another one (if i find it more suitable) like on this picture Link
Everything is pretty good, for now. All soldiers, who has the "Rifleman" role properly change it to a new one. But, if you hire new soldiers, all of them will arrive with non-exist role (technically, thay all are Riflemans, but this class is no longer exist), and this would happend Link
The 'Soldier role' menu becomes completely unavailable, and you cannot even change it to any another one.
I can say, that there is a solution: all you need to do, is just create another 'Rifleman' class Link , which unlocks the upper right menu for all new soldiers Link
if developers decided not to fix it, i'm ok with this, because its not so important.
Everyone have fun and be of good cheer