A few Sarrs in my recirculating mini bog had this issue for a while. The tip of the lid begins drying. The plants push out new pitchers regularly and seem to be doing fine overall.
Plans were inoculated with beneficial mites and some time after that when the issue persisted were getting a regular treatment of Azamax (Extract from neem oil).
Other plants in the bog (D. filiformis, Dionaea "Mad Snappy", S. leucophylla x willisii) are doing fine. Could this indicate that there is not enough water?
S. courtii northern x rubra alabamensis
S. purpurea burkeii x flava kimber here even the unopened pitcher is starting to show the problem.
S. x Bugbat