Can confirm that SDDM has trouble unlocking the default keyring. While it always seems to unlock it after a cold boot, at some point trouble arises when logging out and back in again, along with after resuming from suspend / hibernate. In those situations, the keyring remains locked far more often than not. I am experiencing this under Lubuntu 19.04. The issue has been occurring both before and after I migrated data over from an install of Ubuntu Xenial. I have not made changes to sddm configs, as the other user who filed this bug has.
Can confirm that SDDM has trouble unlocking the default keyring. While it always seems to unlock it after a cold boot, at some point trouble arises when logging out and back in again, along with after resuming from suspend / hibernate. In those situations, the keyring remains locked far more often than not. I am experiencing this under Lubuntu 19.04. The issue has been occurring both before and after I migrated data over from an install of Ubuntu Xenial. I have not made changes to sddm configs, as the other user who filed this bug has.