Help my torn Philodendron leaf!!!

I'm sure Several factors can cause this plant to rot. It could be due to overwatering, a pot with poor drainage, or a lack of nutrients. However, overwatering and choosing the wrong pot are more common problems.

Maybe you have cut it.. but pay attention to the humidity too:))

Oh, it must be the humidity! Have you tried keeping it at less than 60%?
If that's the case, you might want to try cutting or pruning the leaves that are causing you trouble.