卸载KDE、安装gdm

sudo apt purge kde-plasma-desktop kde-standard kde-full
sudo apt autoremove

# 安装 GNOME
sudo apt update
sudo apt install gnome gnome-core

# 3设置 GDM 为默认显示管理器
sudo dpkg-reconfigure gdm3

# 重启
sudo reboot

拓展

https://extensions.gnome.org/extension/615/appindicator-support/