If you used the backup function in the LE settings add-on it includes /storage/.kodi/addons in the backup so the restore reinstated the incompatible LE12 add-on version. Just uninstall the add-on (keeping config) and then install the correct one from the LE repo.
I did that and bingo, the new compatible addon has been installed!
I really thank you very much!!!
Cheers,
Michele.