I created a new family tree, and added a few people. I made the name of some of them "Кириллица" (I just copied some Cyrillic word). I could still edit the name, so I thought I could not duplicate your problem. But I noticed in your description of what you did that you didn't say that you clicked on the edit button. You probably did, and just didn't write it down. But just in case you didn't, you have to click on the edit button for the spots where you can change the name to appear. See the picture below.