I’m afraid I’m not much help in this case, I just wanted to let you know you’re not alone. I have the same issue with the fe599. Adding codes works fine, but I can’t delete them from HA.
I think this lock is a bit of a different beast than the deadbolt models (my doors shift too much to use deadbolts reliably) that are talked about on here quite a bit, specifically in this thread: Schlage Connect ZWave Locks. I’ve never had any luck with the lock reporting anything on the “alarm level” or “alarm type” sensor entities that are created in HA; they’re always 0. I also poll the lock every 30 seconds otherwise HA doesn’t represent whether it’s been manually unlocked.
I’ve always hoped for a bit more time to look into this more but it hasn’t been a priority unfortunately.