I just solo’d the first 5 Spartan Ops episodes on Legendary, but the challenge “Episode of Legend” wasn’t completed. I’m assuming more will be released within the 4 days I have to complete it? Or probably just bugged. Just like how 3 out of 8 campaign levels say I’ve done them on Legendary, but I haven’t got the commendation…
Same happened to me. Did you ever restart from the pause menu? I restarted a few times (new gauss, choose a different first life loadout) so I figured that’s what went wrong. I already forgot what maps I restarted on (except for the first one, obviously) so I’ll do them again and see if that fixes anything. I’ll try not to forget to report back.
edit: redid the first mission, got the challenge.