What's the timeline for this? My undergrad notes from ~15 years ago have held up without obvious degradation. Those are mostly Jetstream inks on generic paper (some Oxford notebook). I swapped to fountain pens at some point when I discovered Noodler's. Bernanke Blue dries extremely fast. Though my TWSBIs from the time haven't held up well. They were fine when constantly used but they cracked in storage.
It somewhat depends on the humidity and temperature. I have not tested for controls, but I suspect it has to do with the low-viscosity oil component undergoing some process similar to paper chromatography where upon contact with moisture it separates from the pigment seeps to the back of the page.