On a fresh Fedora Silverblue 35 install, I installed Slack and Telegram from flatpak. Everything works great, except for the tray. I do not have the Slack or the Telegram icons in the tray.
As far as I know they are not supposed to be there. You should install some GNOME extension (something like appindicator?).
That is not correct. The extension is not required. I am running another machine with the same version of Gnome 41 on ArchLinux, and I installed Slack and Telegram from flatpak on the Arch box. I do not have the extension on Arch, but I do get the icons on Arch.
I also checked flatseal and the rights match 1:1.
That is correct. On Arch I am using the extension “Unite” that is also showing the tray.
Thank you for your advice.