Hi, my pothos has been struggling with yellowing leaves. At first I thought it was because of the new room it’s in, too much sun etc. I repotted it, which I found it was a bit root bound. After repotting it, it’s been growing amazing, like healthy new leaves, new growth everywhere. But some of the older leaves still are yellowing and have spots. It looks like pest damage, it has the signs, but I don’t see any pests. And once again, the new leaves coming in look ok. What could it be?!