am looking into why the Gnome extensions would stop showing after upgrading from 20.04 to 20.10. After rebooting they are now turning themselves off automatically and if I try to enable then, they do not show in the Top header.
Extensions may not anymore work on a newer version of Gnome Shell, which is at 3.38 in Ubuntu 20.10. Make sure your installed extensions are up to date. "Clipboard Indicator" is updated for Gnome Shell 3.38, so that one should work if you have the correct version installed. The latest supported version of Netspeed is 3.34, so indeed there is a possibility that that extension won't work anymore on 3.38. The same goes for " Sound Input & Output Device Chooser", which at this time is available for Gnome Shell up to 3.36.
