I am sorry. I spent an hour on the phone with an AT&T rep whoe specializes in WP devices (apparently, they do exist), and I was told that if there are problems after the 8.1 update then a hard reset is the only way to "force" a fix. My daughters L1020 is having a few random reboots and did not get Cortana. While that is different from your problem, I suspect the longterm solution will be the same.
Truly hope other L1020 users will have better news for you.