All of my replays have been deleted for no reason at all (09/19/19). No patch update, and still have auto saved highlights. I got the replay on (09/18/19). I really wanted to record a replay and now i cant anymore.
Edit: Just tried to watch the auto saved highlights but it just disconnected me from the game.
I think they added a hotfix for ground targeting abilities which, like a new patch, cleared all highlights and replays.