It's the Legendary enemies. Everything else is, on Hard, reasonably tanky, especially when you factor in combos (both solo and team comboing), but the legendaries regen their shields if you so much as take a breather from your rotation. Not sure if this is a bug, server issue causing NPCs to speed up their behaviours, or an intentional design decision.
u/BioCamden u/BiowareBen and u/BenIrvo might be able to fill us in, assuming they don't have their hands full with the rest of the forums!
Hey! I think I mentioned this somewhere today but yes we agree. We actually took another balance pass on this specific thing over the last few days and made adjustments to shields for enemies, mostly elites and legendaries. Looking at you Outlaw Ranger. These changes won’t make it into the demo unfortunately.
As for the shield regen cooldown and how quickly they refill, we’re going to review those after we see the shield value changes live for a bit. Didn’t want to turn more than one dial at a time in this case.