Teams generates it's own ~/.config/autostart/teams.desktop file which is broken in many ways.
State after initial install before lauching Teams for the first time:
[Desktop Entry] Version=1.0 Type=Application Name=Microsoft Teams - Preview Comment=Microsoft Teams for Linux is your chat-centered workspace in Office 365. Exec=/usr/bin/teams %U Icon=teams Terminal=false StartupNotify=true StartupWMClass=Microsoft Teams - Preview Categories=AudioVideo;Network; MimeType=x-scheme-handler/teams; X-KDE-Protocols=teams
After launching Teams for the first time:
~/.config/autostart/teams.desktop is generateed as a file with mode 644, e.g. not executable and not working as an autostart item.
And Exec line reveals another issue why it would not work:
/usr/share/teams/electron: No such file or directory
[Desktop Entry] Version=1.0 Type=Application Encoding=UTF-8 Name=Microsoft Teams - Preview Exec=/usr/share/teams/electron %U Icon=teams Terminal=false StartupNotify=false Categories=Network;Application; MimeType=x-scheme-handler/teams; X-GNOME-Autostart-enabled=true X-KDE-Protocols=teams
How to temporarily fix:
cd ~/.config/autostart rm teams.desktop ln -s /usr/share/applications/teams.desktop teams.desktop
I'm not entirely sure if ~/.config/autostart/.desktop -entries are supposed to be symlinks to /usr/share/applications/.desktop -files, but that seems to work and yields 50% less files and only one file to update in case something has to be changed.