Moving tabs to first or last doesn't work

[NN---]

These shortcuts should work.

https://support.mozilla.org/en-US/kb/keyboard-shortcuts-perform-firefox-tasks-quickly

Move Tab in focus to start | Ctrl + Shift + Home
-- | --
Move Tab in focus to end | Ctrl + Shift + End

[ariasuni]

It seems to be a bug of Firefox in general, because I can reproduce this bug without having the extension installed.

[ariasuni]

I opened a bug report so hopefully they will fix this:

https://bugzilla.mozilla.org/show_bug.cgi?id=1586540

[ariasuni]

They decided to not fix this, you can read the discussion in the bug report.

The shortcuts actually work but not like you expect, it is explained that «in focus» means that the tab bar has been has been focused with tab.