There are a lot of debuffs and some buffs that can make it disappear. It's a bug that's been being reported for a while now but recently they did reply to a couple threads on it asking for videos, and people provided videos showing the bug. So far what I've seen are these effects removing restoration (even if it's restoration x2 and 12 seconds left). It doesn't matter if it's a red health bar enemy or yellow, they all do it and it's nearly every time these debuffs or buffs get applied. Colossus blinding missiles Hive Wizard black cloud Taken Captain black bubble Scorn stasis lantern carriers Grasp of Avarice burdens of riches (picking up engrams) Fallen web mines Restorative light pools in some missions like the severance (it lasts only 4 or 5 seconds and will wipe out 12 seconds of restoration) I'm sure I'm missing a few things that remove it, but I'd say it's fairly safe to assume that if it's a debuff that slows you in any way or freezes you it'll likely remove your restoration and some buffs that give you a bit of healing may remove it too even if they don't last as long and/or aren't as powerful. I didn't notice it as much on my hunter or titan, probably because they can get restoration back so easy. I noticed it a LOT on my warlock when I'd put down a rift, get restoration, only to have it immediately removed by some minor debuff which kind of screws the warlock over since the rifts have a lengthy cooldown compared to the hunter and titan class ability. That and you're going to be stationary if you want to actually use your rift and the bonus to damage it gives. Hope now that they have videos showing this bug in action both from creatures and from the grasp of avarice engrams we'll get a fix soon or at least an update on it.