A Planner Conundrum (HELP!!!)

This year I’ve been using the Clever Fox planner, and I love it! I was worried I wouldn’t like an undated planner, but it hasn’t been a problem at all filling in the dates. As a reminder, the left side pages are daily… … and the right side has room for all sorts of things- I’m still figuring out how to use all this space. It was all going so well, until a few days ago I noticed something strange. On the outer sides of the pages, about a third of the way down the page, the writing has DISAPPEARED. It’s like that on every single page. As you can see, the top portion of the pages are okay, as well as the writing further towards the center. WHAT HAPPENED? I have several half-baked theories, none of which really make sense: 1). I used erasable pens. But “erasable ink” is not the same as “disappearing ink.” Plus, it’s actually kind of hard to erase this ink- you really have to work at it. It doesn’t come off easily. Also, why would it only be on part of the page? 2) I left my planner in the car and the heat damaged it. But again, why would ink have disappeared from only part of each page??? 3) Something spilled on that part of my planner. But I’m pretty sure I would remember spilling something all over my planner- it would be a pretty major spill since all the pages are affected. Also, there’s no sign of water damage. I’m baffled. And seriously, this is not okay! I mean I guess I could practice letting go, and treat my planner as a big sand mandala (as Nicole talked about in her recent post) but I’d rather not. When I write something down I’d like it to stay there. Does anyone have any ideas about this? I would love to have an explanation, because right now I feel like I’m living in an episode of the Twilight Zone. Please tell me your thoughts!