For admin, we can drag that button:
捕获.JPG
For regular users, it disappears and the panel shape is fixed:
捕获2.JPG
Funny story but this bug caused me like half a days worth of trying to find whats wrong. When setting up the nodebb I made an admin with ' in its username. Results were weird to say the least. I could login, but I couldn't actually do anything when I did it, most of the buttons were not working. Basically usernames are sacred for some reason.