Schefflera issue! Yellowing leaves that are in the middle of the plant. There is fresh new growth at the top during this. Had 1+yr w/o issue and now half the plant (3.5ft) is dying. It gets great light; watered according to water meter; occasional fertilizer. Has had scale infestation with lots of sticky honeydew before and hasn’t had yellowing leaves like this. Manually remove scale every few months. Use systemic. None of those things should cause this though. Any thoughts?