Thank you for taking the time to report this bug and helping to make Ubuntu better. I believe what you are experiencing is actually the correct default behavior. Say you changes from Human theme to the Mist theme it will continue to be called Mist until you do something to customize that theme's control, colors, window borders, icons, or pointer. Once you do that the theme is changed to custom theme because you customized it. This is beneficial because then you can save that particular customized theme so that you may reuse it later. If you have any questions please ask. Thanks!
Thank you for taking the time to report this bug and helping to make Ubuntu better. I believe what you are experiencing is actually the correct default behavior. Say you changes from Human theme to the Mist theme it will continue to be called Mist until you do something to customize that theme's control, colors, window borders, icons, or pointer. Once you do that the theme is changed to custom theme because you customized it. This is beneficial because then you can save that particular customized theme so that you may reuse it later. If you have any questions please ask. Thanks!