1. Getting spotted while opening quest objective chests, by NPCs that don't exist, literally no one around. Main reason for this, is number three.
2. Quest objective chests spawning in front of NPCs, that have no movement patterns, which goes along with number three. (only seen these NPCs in the sewer heist.)
3. When opening quest objective chests in heists, the stealth eye, opens fully, revealing you, even with no one around. If there are NPCs that have no movement pattern watching the chest, then there is no way to open it without being spotted.