per Daniel Dawson (desenvolupador) a jul. 6, 2015 · enllaç permanent

Please look at the support forum at https://groups.google.com/forum/#!forum/ddawson-addonssupport
In short, SPE has never claimed to fill passwords. That's still left as the job of Firefox, as to do otherwise would turn SPE into a password manager, not a password *editor*. If Firefox doesn't do that properly, you'll need other solutions, one of which I suggest at aforementioned support site.

If you want to complain about this, please complain to Mozilla developers.