Hello, I was wondering if someone might know what issue my Schefflera arboricola is having. I’ve repotted to check for root rot and couldn’t see any rotting. I’ve potted in a well-draining tropical mix for soil. Watering about every 14 days, depending on when the soil dries out. The plant is getting black/ brown spots on the edges of leaves. I can’t see any parasites and chopped off the top where the leaves were having the most problems, as I thought it could be from top watering at the greenhouse. Do I need to treat with something?