Unfortunately if something fails while changing between modes, the next time you run kali-undercover it will save your undercovered desktop as if it was your customized desktop. So changing between them gives no difference. You can try restoring your desktop running:

rm -rf .config/xfce4 .local/share/kali-undercover && reboot

This report has been filed against an old version of Kali. We will be closing this ticket due to inactivity.

Please could you see if you are able to replicate this issue with the latest version of Kali Linux (https://www.kali.org/get-kali/)?

If you are still facing the same problem, feel free to re-open the ticket. If you choose to do this, could you provide more information to the issue you are facing, and also give information about your setup?
For more information, please read: https://www.kali.org/docs/community/submitting-issues-kali-bug-tracker/