答案1
问题出在安装了 Unity 及其指示器之后。完全删除 Unity 及其所有指示器后,图标恢复原状:
这是您应该安装的名称中带有“indicator”的软件包列表:
$ apt list --installed | grep indicator
gnome-shell-extension-appindicator/cosmic,cosmic,now 22-1 all [installed]
libappindicator1/cosmic,now 12.10.1+18.04.20180322.1-0ubuntu1 amd64 [installed,automatic]
libappindicator3-1/cosmic,now 12.10.1+18.04.20180322.1-0ubuntu1 amd64 [installed]
libindicator3-7/cosmic,now 16.10.0+18.04.20180321.1-0ubuntu1 amd64 [installed]
libindicator7/cosmic,now 16.10.0+18.04.20180321.1-0ubuntu1 amd64 [installed,automatic]