Why does water sit pull on top of my charcoal inserts??

Noradun • 🌸Due in Sept 2019 with 🌈 after TTC 3.5 yrs with PCOS👣Mommy of 5 💑 Married for 14 yrs👩🏼‍🎓Graduating in 2019 👩🏼‍💻 WFH Mom 🌼

I have hundreds of charcoal inserts, I have been selling all of my MF inserts! I was curious and I ran water on my charcoal insert and the water pulled on top of the charcoal! It immediately absorbed in my MF brand! I thought the leak issues we had were from the MF I was using (I though compression leaks) but if the charcoal isn’t absorbing, or if it is slow to absorb, wouldn’t that explain it!? Should I be selling my charcoal inserts too??