Ant
Your one and only pest!
Recently the immature H. hispida has had a large pitcher die off. The only thing that has changed would be the seasons, but because the windows are open now it should still be experiencing a nightly temperature drop. I have been growing it in a plastic bag with the top open. (to keep a higher humidity inside but still allow air exchange) The plant has almost entirely filled its pot with like pitchers before this happened, paused growth, then resumed growth as the pitchers started to brown. All the larger pitchers are still green and healthy and it will not budge with given a gentle tug. (so it isn't rot?) I could only think of three reasons, over crowding, over heating, or its normal. I will get pictures tomorrow if I need too.