You can try removing the device from your Firefox Account and then adding it again. Changing the names may take a while to reflect across all devices.

Your list of devices in your Firefox Account can be found by clicking here.

Hope this helps.

Wesley Branton said

You can try removing the device from your Firefox Account and then adding it again. Changing the names may take a while to reflect across all devices. Your list of devices in your Firefox Account can be found by clicking here. Hope this helps.

In the "Devices and apps" section everything is normal, but when I try to send a tab to another device I get 3 additional devices that don't show up there, thus I cannot disconnect.

Did you try to restart Firefox to update the list of connected devices?

cor-el said

Did you try to restart Firefox to update the list of connected devices?

The behavior is consistent with all connected devices, even the latest added one. It must have something to do with Sync, not the browser itself

Have you tried removing the device from the Firefox Account settings as I suggested? Even if everything is normal on there, removing the device may still remove the duplicate items from Firefox Sync.

Wesley Branton said

Have you tried removing the device from the Firefox Account settings as I suggested? Even if everything is normal on there, removing the device may still remove the duplicate items from Firefox Sync.

I removed it and added it again three times, twice I tried the same name and that name appears also twice.

Try removing again and temporarily disabling sync on it and one other device and restarting sync. A long version of a forced re-sync.

Corey 'linuxmodder' Sheldon said

Try removing again and temporarily disabling sync on it and one other device and restarting sync. A long version of a forced re-sync.

It persists even on the new device after I installed the regular Firefox

In case of issues with Sync you can try this:

Disconnect from Sync and Reconnect to Sync again. You can disconnect from Sync by clicking the e-mail address in the "3-bar" Firefox menu button drop-down list or go to "Options/Preferences > Sync".

Delete the signedInUser.json file in the Firefox profile folder and delete the Weave folder (Sync was formerly named Weave) with Firefox closed.

Remove an existing chrome://FirefoxAccounts entry in the Firefox Password Manager.

If that isn't enough then delete the prefs.js files to reset all prefs and maybe also delete the compatibility.ini file to reinitialize the profile.

Delete and re-create the Firefox account or change the Sync password. Note that changing the Sync password will wipe all data stored on the Sync server.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

cor-el said

In case of issues with Sync you can try this: Disconnect from Sync and Reconnect to Sync again. You can disconnect from Sync by clicking the e-mail address in the "3-bar" Firefox menu button drop-down list or go to "Options/Preferences > Sync". Delete the signedInUser.json file in the Firefox profile folder and delete the Weave folder (Sync was formerly named Weave) with Firefox closed. Remove an existing chrome://FirefoxAccounts entry in the Firefox Password Manager. If that isn't enough then delete the prefs.js files to reset all prefs and maybe also delete the compatibility.ini file to reinitialize the profile. Delete and re-create the Firefox account or change the Sync password. Note that changing the Sync password will wipe all data stored on the Sync server. You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I tried these suggestions but they didn't work, too much browser specific I think. Then I tried to change the password, now on all devices I can only share to the ghost devices, the real ones are not displayed anymore... (in "Devices & apps" section everything is regular) and the Sync feature is broken, evn though the arrows spin and it appears working normally, nothing is actually synced between the devices. What to do?

NOTE TO CONTRIBUTORS: This thread could also be related to Device name change not propagated to other devices.

I got this problem too. My version is with Firefox 52.9.0esr in Win 7