I just installed Ubuntu 18.04 and decided to install Slack via deb, which turns out to uninstall my version of virtualbox and other necessary packages. So I uninstalled the deb, and installed with snap. I don’t have an icon on the tray, but I do see an icon on the dock and in the app switcher.
I’ve rebooted but no change. I’ve read every post here, but it seems there’s no workaround to fix the tray icon. Does anybody know how to fix this?
EDIT: The problem was not Slack but TopIcons Plus, I decided to switch to Appindicator extension and now the icon is working.