As original reporter, I can confirm that the xprop trick works around this problem.
I used a modification of the wrapper script from #12, after sudo apt install wmctrl # as of recent https://github.com/xeyownt/xseticon/pull/4 sudo snap install xseticon and adjusting the icon path to use the snap ICON=/snap/slack/current/usr/lib/slack/resources/app.asar.unpacked/src/static/slack.png and using this for the xseticon binary path: /snap/xseticon/current/bin/xseticon -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1827302 Title: 18.10 → 19.04 Alt-Tab cycling no longer includes Slack window To manage notifications about this bug go to: https://bugs.launchpad.net/xfwm4/+bug/1827302/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs