Holy sh33t! Exactly opposite happened to me... kept dying out of nowhere, even when I was away from all those flying poppy leaves! Just random death kicked in. That's when I thought let me just get FAR AWAY from the poppy fields after getting each objective completed out there. That worked for the greater part of the mission but then... problem was that strange things/ hallucinations started happening amongst those sleep inducing poppy plants and the game would magically give me a long black screen (like my character almost fainting) and then spawned me away from the last objective repeatedly... that's when it got very annoying!
Game definitely has it's fair share of bugs right now. Definitely needs a patch/ patches.