Wait are you guys farming the The Old Sentinel or Guardian Vyn? Because the Chrono Key doesn’t drop from the final boss 
Um, @Gulfwulf and I are referring to the map, not the boss. We play the whole map, we don’t just get to the right miniboss and quit.
Ah my mistake, carry on 
Just lousy luck I’d say. Over 3 weeks worth of playing I’ve only ever found 2 legendaries, but yesterday found 2 in a single match of advanced Algorithm, including the poor m-pulse controller.
If anything, I feel their higher. I got 4 in the last two days. Run it with a full group so you get 5 rolls instead of one. Soloing is brutal.
Funnily enough I got 3 legendary items yesterday, 2 from a single mission and 1 from a loot pack. I was mainly observing a shift from Rares and epics to common and uncommon. RNG still hasn’t forsaken me.
Did you get the hostile takeover also by chance?
I have to echo this though, despite the voices of others, I have noticed a distinct and over bearing amount of ‘green’ (can nolonger call it uncommon because it is now theeee most commonly occurring gear) in the past week of constantly farming The Old Sentinel stage. Strangest thing was the moment I went to a random match landing on The Algorithm we got two legendaries (M-Pulse & Hostile Takeover). Also 53 Jennerit packs later I have only one legendary but a ton of skins and taunts and a few 1000 credits packs (Caldarius is fully unlocked lol).
Full group is always better than solo if you were running solo